| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J. Biol. Chem., Vol. 275, Issue 31, 23884-23890, August 4, 2000
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From the Laboratory of Biochemistry, Faculty of Science, Kochi
University, Kochi 780-8520, Japan
Received for publication, April 6, 2000, and in revised form, May 9, 2000
Arginine kinases were isolated from the
cephalopods Nautilus pompilius, Octopus
vulgaris, and Sepioteuthis lessoniana, and the
cDNA-derived amino acid sequences have been determined. Although the origin and evolution of cephalopods have long been obscure, this
work provides the first molecular evidence for the phylogenetic position of Cephalopoda in molluscan evolution. A crystal structure for
Limulus arginine kinase showed that four amino acid
residues (Ser63, Gly64, Val65, and
Tyr68) are hydrogen-bonded with the substrate
arginine. We introduced three independent mutations, Ser63
Phosphagen (guanidino) kinases constitute a family of highly
conserved enzymes, which catalyzes the reversible transfer of phosphate
from phosphagen such as creatine phosphate to ADP. Creatine kinase
(CK),1 the most widely
studied member of this family, plays a central role in both temporal
and spatial ATP buffering in cells that display high and variable rates
of energy turnover (1, 2). The crystal structures have been
determined for chicken mitochondrial CK (3) and muscle and
brain CKs (4, 5). The remaining major members of this family (arginine
kinase (AK), glycocyamine kinase (GK), lombricine kinase (LK),
taurocyamine kinase (TK)) have not been investigated as extensively as
CK but likely play a similar physiological role (2, 6, 7).
Arginine kinase (AK) is widely distributed in the lower and higher
invertebrate groups and is present in many lower chordates but absent
in the vertebrates (6, 8). Interestingly, AK evolved at least twice
during evolution of phosphagen kinases: first, at an early stage of
phosphagen kinase evolution (its descendants are molluscan and
arthropod AKs) and second, from CK at a later time in metazoan
evolution (9). Conventional wisdom would suggest that AK is the most
primitive member of the phosphagen kinase family and that the other
members, including CK, arose from tandem gene duplications and
subsequent divergence (6, 10, 11).
From an earlier amino acid sequence alignment of CKs, GK, LK, and AKs,
we proposed that a region displaying remarkable amino acid deletions
(referred to as the guanidino specificity (GS) region) was a
possible candidate for the guanidino recognition site (12). This GS
region is overlapped partly by the so-called flexible loop in the
crystal structures of chicken mitochondrial CK (3) and
Limulus AK (13). There is a proportional relationship between the size of the deletion in the GS region and the mass of
guanidine substrate used (12). Among the amino acid residues in the GS
region, we noted previously that the seventh residue, Asp, is conserved
in all AK sequences but not in other phosphagen kinases. This residue
is not associated with the substrate binding (13), but we assumed that
it has a special role in the recognition of the substrate arginine
(14).
Mollusks constitute one of the most diverse animal phyla. Living
representatives are classically divided into seven classes, of which
major ones are Bivalvia, Gastropoda, and Cephalopoda. There are several
hypotheses concerning molluscan phylogeny based on morphological
features, but the results are still controversial. Sequence comparisons
using 18S RNA, 12S rRNA, or mitochondrial DNA have been used to solve
the complicated phylogeny of molluscan classes except Cephalopoda
(15-19). However, molecular analyses have not resulted in a clear
determination for the phylogeny. Thus, the origin and evolution
of cephalopods have long been obscured by the poor fossil record and
molecular data.
Nautilus pompilius is the only living representative of the
large extinct group of nautiloids, ammonites and belemnites, and is
sometimes referred to as a living fossil, like Latimeria and Lingula. In this report, first, we determined the
cDNA-derived amino acid sequences of AKs from three cephalopods
N. pompilius, Octopus vulgaris, and
Sepioteuthis lessoniana (squid) to elucidate the evolution
of molluscan AKs. Next, we examined the functional role of several
amino acid residues on the GS region of Nautilus AK by
site-directed mutagenesis. In particular, we focused on functional
significance of Asp62, which is not associated with the
substrate binding but is conserved in all AK sequences.
Throughout this report, the sequence numbering of Limulus AK
(20) is used. The actual sequence number in Nautilus AK,
used in the mutagenesis studies, can be obtained by subtracting 6 from the Limulus numbering.
Isolation of Arginine Kinases--
All procedures were carried
out at 4-8 °C. The body wall muscle (10 g) of Nautilus,
Sepioteuthis, or Octopus was homogenized with 50 ml of 10 mM Tris acetate buffer (pH 8.1) containing 0.1 mM dithiothreitol. The tissue extract was fractionated with
60-80% saturated ammonium sulfate. The precipitate was dissolved in a minimum volume of the same buffer, and applied to a Sephadex G-75 column (3 × 115 cm) equilibrated with the same buffer. The
fractions possessing AK activity were pooled and applied to a DEAE-5PW
column (7.5 × 75 mm, Tosoh) equilibrated with 20 mM
Tris acetate buffer (pH 8.1) containing 0.2 mM
dithiothreitol. The column was washed with the same buffer and then
eluted with a linear gradient of 0-500 mM NaCl in 20 mM Tris acetate buffer. The purified AK was stored on ice
or at
Enzyme activity was assayed spectrophotometrically at 25 °C (7).
Protein concentration was estimated from the absorbance at 280 nm (the
absorbance 0.77 at 280 nm in a 1-cm cuvette corresponds to 1 mg of
protein/ml).
SDS-polyacrylamide gel electrophoresis (PAGE) was carried out in 15%
acrylamide gels containing 0.087%
N,N'-methylenebisacrylamide, 0.375 M
Tris-HCl (pH 8.8) and 0.1% SDS. The sample was incubated in 0.75% SDS
at 100 °C for 5 min in the presence of 2-mercaptoethanol before electrophoresis.
Partial Amino Acid Sequence Determination--
The isolated
proteins were pyridylethylated and digested with lysyl
endopeptidase at an enzyme/substrate ratio of 1:100 in 0.1 M Tris-HCl (pH 8.0) at 37 °C for 6 h. The digested
products were isolated by reverse-phase chromatography. The column
(Cosmosil 5C18-300, 4.6 × 150 mm) was equilibrated
with 0.1% trifluoroacetic acid and eluted with a linear gradient of
0-90% acetonitrile in 0.1% trifluoroacetic acid over 90 min at a
flow rate of 1 ml/min. Peptides for sequence analysis were purified
further by rechromatography on the same column with a linear gradient
of acetonitrile in 10 mM ammonium acetate. The amino acid
sequences of the whole protein and peptides were determined using an
automated protein sequencer (Applied Biosystems 476A).
cDNA Sequence Determination--
mRNA was prepared from
the radular muscle of Nautilus, Sepioteuthis, or
Octopus with a QuickPrep Micro mRNA purification kit (Amersham Pharmacia Biotech). The single stranded cDNA was
synthesized with reaction beads (Ready-To-Go You-Prime First-Strand
Beads, Amersham Pharmacia Biotech) using the oligo-dT adapter as a
primer. The 3' half of the cDNA was first amplified for 30 cycles,
each consisting of 1 min at 94 °C for denaturation, 1 min at
55 °C for annealing, and 1.5 min at 72 °C for primer extension by
polymerase chain reaction (PCR). Extra Taq DNA polymerase
(Takara) was used as the amplifying enzyme. The primers used are the
oligo-dT adapter and a 512-fold "universal" redundant oligomer,
5'-GT(A/C/G/T)TGG(A/G)T(A/C/G/T)AA(T/C)GA(A/G)GA(A/G)GA(T/C)CA, designed for amplification of phosphagen kinases (21). The amplified products were sequenced directly with dye terminator cycle sequencing FS ready reaction kit using a Model 373-18 DNA sequencer (Applied BioSystems). The universal redundant oligomer was used as a sequence primer.
The 5' half of the cDNA was amplified as follows. The single
stranded cDNA was newly synthesized with the nonredundant primer (Nauti.R1 for Nautilus, Sepio.R1 for
Sepioteuthis, and Octo.R1 for Octopus), and the
poly(A)+ tail was added to the 3' end with terminal
deoxynucleotidyl transferase. Then the 5' half of the cDNA was
amplified by the method described above, using the oligo-dT adapter and
the nonredundant primer (Nauti.R2 for Nautilus, Sepio.R2 for
Sepioteuthis, and Octo.R2 for Octopus). The
amplified products were sequenced directly.
Expression of Wild-type Nautilus AK and Site-directed
Mutagenesis--
The open reading frame of 1053 base pairs (bp) of
Nautilus AK was cloned into the
BamHI/HindIII site of pMAL-c2
(pMAL/NautilusAK-wild). The maltose binding
protein-Nautilus AK fusion protein was expressed in
Escherichia coli TB1 cells by induction with 1 mM isopropyl-1-thio-
The mutations (Asp62 (GAC) Arginine kinases (AKs) from the body wall muscles of
Nautilus, Octopus, and Sepioteuthis
were purified to homogeneity using ammonium sulfate fractionation,
Sephadex G-75 gel filtration and DEAE-5PW chromatography. SDS-PAGE, in
the presence of a reducing agent, showed that the isolated AKs were
highly purified, and the molecular masses were about 40 kDa. The AKs
were confirmed to be monomers on the gel filtration column. No
N-terminal amino acid of the AKs was detected by protein sequencing,
indicating that N termini were blocked. The isolated enzyme was
pyridylethylated and digested with lysyl endopeptidase. The peptides
were purified by reverse-phase chromatography, and some peptides were
sequenced (Fig. 1, A-C).
The enzymatic parameters, Km for arginine and
Vmax, of the isolated AK enzymes from
Nautilus, Octopus, and Sepioteuthis were obtained at 25 °C for the forward reaction (Table II).
The Km values ranged
from 1.0 to 2.8 mM, whereas the Vmax values ranged from 4.3 to 10.4 µmol of Pi/min/mg of
protein. These values are comparable to other molluscan AKs
(Solen, Meretrix, and Aplysia)
determined under the same conditions.
Arginine Kinase from Nautilus pompilius, a Living
Fossil
SITE-DIRECTED MUTAGENESIS STUDIES ON THE ROLE OF AMINO ACID
RESIDUES IN THE GUANIDINO SPECIFICITY REGION*
,
ABSTRACT
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
Gly, Ser63 Thr, and Tyr68 Ser, in
Nautilus arginine kinase. One of the mutants had a considerably reduced substrate affinity, accompanied by a decreased Vmax. In other mutants, the activity was lost
almost completely. It is known that substantial conformational changes
take place upon substrate binding in arginine kinase. We hypothesize
that the hydrogen bond between Asp62 and Arg193
stabilizes the closed, substrate-bound state. Site-directed mutagenesis studies strongly support this hypothesis. The mutant (Asp62
Gly or Arg193 Gly), which destabilizes the
maintenance of the closed state and/or perhaps disrupts the unique
topology of the catalytic pocket, showed only a very weak activity
(0.6-1.5% to the wild-type).
INTRODUCTION
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
MATERIALS AND METHODS
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
80 °C until use.
-D-galactopyranoside at
27 °C for 18 h. The soluble protein was extracted with B-PER reagent (Pierce), and the fusion protein was purified by affinity chromatography using amylose resin (New England BioLabs). The enzyme assay was done using the purified fusion protein.
Gly (GGC), Asp62
(GAC) Glu (GAG), Ser63 (AGT) Gly (GGT),
Tyr68 (TAC) Ser (TCC), and Arg193 (AGA) Gly (GGA)) were introduced in the template of
pMAL/NautilusAK-wild by PCR using mutation-primers (the
sequences are shown in Table I).
Pfu DNA polymerase was used as the amplifying enzyme. The PCR products were digested with DpnI, and the target 7000-bp
DNA was recovered by EasyTrap (version 2, Takara). After blunting and
kination, the DNA was self-ligated. The mutated protein was expressed as described above. The mutated cDNA insert was
sequenced completely, and it was confirmed that there is no unexpected
mutation.
Primers used for site-directed mutagenesis of Nautilus AK
RESULTS
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
View larger version (53K):
[in a new window]
Fig. 1.
Nucleotide and derived amino acid sequences
of cDNAs of N. pompilius (A), O. vulgaris (B), and S. lessoniana
(C) AKs. Arrows indicate primers used for
amplification. Amino acid sequences determined chemically are shown by
dotted lines.
Enzymatic parameters of molluscan AKs
The 3' halves of the cDNAs of Nautilus, Octopus, and Sepioteuthis AKs were amplified by PCR with the phosphagen consensus primer and oligo-dT adapter. Then two new oligomers were designed for amplification of the 5' halves. These 3' and 5' products were sequenced directly, and the nucleotide sequences of 1227 bp for Nautilus, 1226 bp for Octopus, and 1306 bp for Sepioteuthis were determined (Fig. 1, A-C). The open reading frame for Nautilus AK is 1053 nucleotides in length and encodes a protein with 350 amino acid residues; those for Octopus AK, 1044 nucleotides and 347 residues; those for Sepioteuthis AK, 1047 nucleotides and 348 residues. The validity of the cDNA-derived amino acid sequences was supported by chemical sequencing of internal lysyl endopeptidase peptides (81 amino acid residues determined for Nautilus, 36 residues for Octopus, 43 residues for Sepioteuthis). The molecular masses were calculated to be 39,276, 39,176, and 39,040 Da, respectively, consistent with the values estimated by SDS-PAGE. The nucleotide and amino acid sequences has been submitted to the DDBJ (accession numbers AB042330 for Nautilus, AB042331 for Octopus, and AB042332 for Sepioteuthis).
The recombinant maltose binding protein/Nautilus AK (wild
type) gave enzymatic parameters Km (0.68 mM) and Vmax (7.64 µmol of
Pi/min/mg of protein) similar to those of the native
enzyme. Those for the mutated Nautilus AKs are listed in
Table II.
| |
DISCUSSION |
|---|
|
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
Evolution of Cephalopod AKs and Phylogenetic Position of Nautilus
The cDNA-derived amino acid sequences of Nautilus,
Octopus, and Sepioteuthis AKs were aligned with
that of Limulus (horseshoe crab) AK (20) in Fig.
2, which is the only AK whose crystal structure is known (13). The sequence of Nautilus AK showed high percentage identity (69-73%) with those of Octopus
and Sepioteuthis AKs. The identity between
Octopus and Sepioteuthis AKs is 83%. These
cephalopod AK sequences still have a strong homology (53-55%) with
that of the arthropod Limulus AK.
|
We have constructed a phylogenetic tree with the maximum likelihood
method (22) for 36 cDNA-derived amino acid sequences of AK, CK, GK,
and LK so far known, including four major molluscan classes Bivalvia,
Polyplacophora, Gastropoda, and Cephalopoda. In Fig.
3, a part of the tree with all molluscan
sequences is shown. The similar topology is obtained with the
Neighbor-Joining method (23). The tree clearly shows that the sequences
of the clams Pseudocardium, Solen, and
Corbicula (Bivalvia) diverged first in molluscan AKs and was
followed by the radiation of Polyplacophora (chiton
Liolophura), Gastropoda (Nordotis,
Battilus, Cellana, and Aplysia), and
Cephalopoda (Nautilus, Octopus, and
Sepioteuthis). Although the tree could not make clear the
order of divergence of the three classes Polyplacophora, Gastropoda,
and Cephalopoda, it suggests that the biological position of the chiton
Liolophura, which is believed to be one of the primitive
molluscs, should be reconsidered. Although the origin and evolution of
cephalopods have long been debated, this work provides the first
molecular evidence, as far as we know, for the phylogenetic position of Cephalopoda in molluscan evolution. Consistent with the morphological data, the branching pattern in Cephalopoda suggests that
Nautilus (subclass Tetrabranchia, order Nautiloidea) is the
most primitive, and Octopus (subclass Dibranchia, order
Octapod) and Sepioteuthis (subclass Dibranchia, order
Decapoda) share a common immediate ancestor.
|
We described before that the amino acid sequences of molluscan AKs could be used as a molecular clock to elucidate the divergence time of molluscs, because the enzymes appear to be derived from a single gene strain and have a moderate evolutionary rate (24). A maximum likelihood clock-like tree constructed from the 36 amino acid sequences allows us to estimate the divergence time of the interested molluscan species. If we assume the divergence between Mollusca and Arthropoda occurred about 550 million years before present (25), the radiation time of Polyplacophora, Gastropoda, and Cephalopoda is estimated to be 290 million years before present (data not shown).
Role of Amino Acid Residues of the GS Region in AK Function
Substrate-binding Residues--
Amino acid sequences around the GS
region of phosphagen kinases are shown in Fig.
4. This GS region is overlapped partly by the so-called flexible loop in the crystal structure of chicken mitochondrial CK, which has been speculated to move nearer to the
active site to exclude water during catalysis (3). Clearly, there is a
proportional relationship between the size of the deletion in GS region
and the mass of guanidine substrate used. Namely, LK and AK, which use
relatively large guanidine substrates, lombricine and arginine, have a
five-amino acid deletion in this region, CK has one amino acid
deletion, and GK has no deletion. It is possible that the introduction
of an amino acid deletion as in the GS region in Fig. 4 shortens the
flexible loop and allows the active site to accommodate a larger
guanidine substrate.
|
Recently, a crystal structure for the transition state analog complex (TSAC) of the AK from the horseshoe crab Limulus has appeared (13). The structure showed that four amino acid residues (Ser63, Gly64, Val65, and Tyr68 in Limulus AK sequence), located in the GS region (see Fig. 4), are hydrogen-bonded with the amino and carboxylate groups of the substrate arginine. These residues are conserved in all three AK sequences from Nautilus, Octopus, and Sepioteuthis, suggesting that the substrate-binding mechanism of cephalopod AKs is the same as that of Limulus AK.
Among molluscan AKs, the four residues associated with substrate binding are conserved in most AKs. However, residue 64 or 65 is replaced by Ser, Lys, or Cys in the two-domain AKs from the clams Pseudocardium, Corbicula, and Solen and the sea anemone Anthopleura. Thus it appears that the two-domain AKs may have a unique substrate-binding system.
We introduced two independent mutations, Ser63 Gly and
Ser63 Thr, in the 63rd position of Nautilus
AK (Table II). At least one of the mutant proteins (Ser63
Gly) had a considerably reduced substrate affinity
(Km = 3.45 mM) compared with the wild
type (Km = 0.68 mM), accompanied also by
a decreased Vmax (less than 5% to the
wild-type). In the case of Ser63 Thr mutation, the AK
activity was lost almost completely, probably due to a steric hindrance.
The Tyr68 is conserved in all AKs, including two-domain
clam AKs, except in the sea cucumber Stichopus AK, which
evolved not from the AK gene but from the CK gene (9).
Stichopus AK has a completely different substrate-binding
system (see the sequence of Stichopus AK in Fig. 4), which
will be described elsewhere. The aromatic side chain of
Tyr68 forms a hydrogen-bond with the amino group of the
substrate arginine in Limulus AK, and thus the
Tyr68 appears to be the most important residue in substrate
binding. Consistent with this, the enzyme activity of
Nautilus Tyr68 Ser mutation was lost
completely (Table II).
Role of Asp62-- We noted previously that the Asp62 in the GS region is conserved in most AK sequences, including Stichopus AK, which evolved from the CK gene, but not in other phosphagen kinases CK, GK, and LK (9, 14) (see Fig. 4). The TSAC crystal structure of Limulus AK indicates that Asp62 is not associated with the substrate binding, and the authors have not referred to any functional role (13). On the other hand, we assumed previously that Asp62 has a special role in the recognition of the substrate, arginine (14), and the first domain of Pseudocardium two-domain AK might not retain a complete enzyme activity, because the Asp62 was replaced by a Gly residue (Fig. 4).
The TSAC structure of Limulus AK indicates that it consists
of two domains; an N-terminal small 
-helical domain (N-domain) of
residues 1-111 and a C-terminal domain (C-domain) possessing an
8-stranded antiparallel -sheet flanked by 7 -helices of residues 112-357 (13). One of the two substrates, ATP or ADP, is accommodated in the C-domain, and another substrate, arginine or arginine phosphate, contacts mainly with the N-domain. The catalytic center, where reversible transfer of the phosphate occurs, is located in the C-domain. We found that in the TSAC structure of Limulus AK,
viewed by SwissPdbViewer (PDB Id: 1BG0), the side chain of
Asp62 in the N-domain is hydrogen-bonded with that of
Arg193 in the C-domain (Fig.
5), and that Arg193 is
conserved in all AKs. Here we hypothesize that the hydrogen bond
between Asp62 and Arg193 plays a crucial role
in AK function, namely, that the two domains are maintained in a
favorable topology by the hydrogen bond, where the two kinds of
substrates are accessible enough for reaction.
|
If the 3-dimensional structure of Nautilus AK is homologous
with that of Limulus AK (13), site-directed mutagenesis
studies using Nautilus AK strongly support the above
hypothesis. Both of the mutations Asp62 Gly and
Arg193 Gly, which break the hydrogen bonding
completely, markedly reduced enzyme activity (less than 1.5% of the
wild-type). The same result was obtained from a mutagenesis study using
the Asp62 Gly mutant of Stichopus
AK.2 In addition, the results
of mutation Asp62 Glu provides strong evidence for the
functional role of Asp62. This mutation, like the former
two mutations, could be expected not to change the substrate affinity
for arginine, but it could be expected to have ability to form a
hydrogen bond with Arg193. Enzymatic parameters are
consistent with this idea; the Km (0.67 mM) is the same as that (0.68 mM) of wild-type,
and the Vmax is reduced largely but not so much
as that of the Asp62 Gly or Arg193 Gly
mutations, probably due to a partial formation of hydrogen bond between
Glu62 and Arg193.
Zhou et al. (13) have suggested that it is the precise orientation of the substrates in the catalytic pocket of AK that dominates the forces driving catalysis. Substantial conformational changes take place upon substrate binding in CK (26). The recent crystal structures of CK (3-5) and AK (13) provide very compelling insight into the nature of these structural changes. The extent domain and flexible loop movements during catalysis have recently been modeled by Forstner et al. (27) for CK and by Zhou et al. (28) for AK.
Our results and the above models show that, upon substrate binding, the
flexible loop bearing Asp62 moves nearer to the active
center to exclude water during catalysis, and the hydrogen bond between
Asp62 and Arg193 is formed to link the N- and
C-domain of AK (Fig. 5). This bond stabilizes the closed,
substrate-bound state. The mutant (Asp62 Gly or
Arg193 Gly) destabilizes the maintenance of the closed
state and/or perhaps disrupts the unique topology of the catalytic
pocket; therefore, these mutants show only a very weak activity
(0.6-1.5% to the wild-type, see Table II). The mutant
(Asp62 Glu), while allowing hydrogen bonding between
Glu62 and Arg193, may also disturb the topology
of the catalytic pocket.
Our results are highly consistent with prevailing views on the
catalytic mechanism of phosphagen kinases. Maintenance of the precise
three-dimensional structure of the active site is critical for optimum
efficiency of enzyme function. Thus, we conclude that Asp62
(or Arg193) is one of the key residues in AK function.
| |
ACKNOWLEDGEMENTS |
|---|
We thank Dr. Ross Ellington for critical reading of the manuscript and giving us helpful suggestions and Takuya Higashi for performing experiments on amino acid sequencing of Nautilus AK.
| |
FOOTNOTES |
|---|
* The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
To whom correspondence should be addressed: Laboratory of
Biochemistry, Faculty of Science, Kochi University, Kochi 780-8520, Japan. Tel.: 88-844-0111; Fax: 88-844-8356; E-mail:
suzuki@sc.kochi-u.ac.jp or suzuki@cc.kochi-u.ac.jp.
Published, JBC Papers in Press, May 12, 2000, DOI 10.1074/jbc.M002926200
2 T. Suzuki, Y. Yamamoto, and M. Umekawa, unpublished.
| |
ABBREVIATIONS |
|---|
The abbreviations used are: CK, creatine kinase; AK, arginine kinase; GK, glycocyamine kinase; LK, lombricine kinase; TK, taurocyamine kinase; GS region, guanidino specificity region; TSAC, transition state analog complex; PAGE, polyacrylamide gel electrophoresis; PCR, polymerase chain reaction; bp, base pair(s).
| |
REFERENCES |
|---|
|
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
| 1. | Meyer, R. A., Sweeney, H. L., and Kushmerick, M. J. (1984) Am. J. Physiol. 246, C365-C377 |
| 2. | Wallimann, T., Wyss, M., Brdiczka, D., Nicolay, K., and Eppenberger, H. M. (1992) Biochem. J. 281, 21-40 |
| 3. | Fritz-Wolf, K., Schnyder, T., Wallimann, T., and Kabsch, W. (1996) Nature 381, 341-345 |
| 4. | Rao, J. K., Bujacz, G., and Wlodawer, A. (1998) FEBS Lett. 439, 133-137 |
| 5. | Eder, M., Schlattner, U., Becker, A., Wallimann, T., Kabsch, W., and Fritz-Wolf, K. (1999) Protein Sci. 8, 2258-2269 |
| 6. | Watts, D. C. (1971) in Biochemical Evolution and the Origin of Life (Schoffeniels, E., ed) , pp. 150-173, North-Holland, Amsterdam |
| 7. | Ellington, W. R. (1989) J. Exp. Biol. 143, 177-194 |
| 8. | Watts, D. C. (1975) Symp. Zool. Soc. Lond. 36, 105-127 |
| 9. | Suzuki, T., Kamidochi, M., Inoue, N., Kawamichi, H., Yazawa, Y., Furukohri, T., and Ellington, R. W. (1999) Biochem. J. 340, 671-675 |
| 10. | van Thoai, N. (1968) in Homologous Enzymes and Biochemical Evolution (van Thoai, N. , and Roche, J., eds) , pp. 199-229, Gordon and Breach, New York |
| 11. | Suzuki, T., Kawasaki, Y., and Furukohri, T. (1997) Biochem. J. 328, 301-306 |
| 12. | Suzuki, T., Kawasaki, Y., Furukohri, T., and Ellington, W. R. (1997) Biochim. Biophys. Acta 1348, 152-159 |
| 13. | Zhou, G., Somasundaram, T., Blanc, E., Parthasarathy, G., Ellington, W. R., and Chapman, M. (1998) Proc. Natl. Acad. Sci. U. S. A. 95, 8449-8454 |
| 14. | Suzuki, T., Kawasaki, Y., Unemi, Y., Nishimura, Y., Soga, T., Kamidochi, K., Yazawa, Y., and Furukohri, T. (1998) Biochim. Biophys. Acta 1388, 253-259 |
| 15. | Winnepenninckx, B., Backeljau, T., and De Wachter, R. (1995) Mol. Biol. Evol. 12, 641-649 |
| 16. | Winnepenninckx, B., Backeljau, T., and De Wachter, R. (1996) Mol. Biol. Evol. 13, 1306-1317 |
| 17. | Steiner, G., and Muller, M. (1996) J. Mol. Evol. 43, 58-70 |
| 18. | Adamkewicz, S. L., Harasewych, M. G., Blake, J., Saudek, D., and Bult, C. J. (1997) Mol. Biol. Evol. 14, 619-629 |
| 19. | Winnepenninckx, B., Backeljau, T., and De Wachter, R. (1994) Nautilus 2 (suppl.), 98-110 |
| 20. | Strong, S. J., and Ellington, W. R. (1995) Biochim. Biophys. Acta 1246, 197-200 |
| 21. | Suzuki, T., and Furukohri, T. (1994) J. Mol. Biol. 237, 353-357 |
| 22. | Strimmer, K., and von Haeseler, A. (1996) Mol. Biol. Evol. 13, 964-969 |
| 23. | Felsenstein, J. (1993) PHYLIP (Phylogeny Inference Package) version 3.5c. , Distributed by the author. Department of Genetics, University of Washington, Seattle, U. S. A. |
| 24. | Suzuki, T., Ban, T., and Furukohri, T. (1997) Biochim. Biophys. Acta 1340, 1-6 |
| 25. | Goodman, M., Pedwaydon, J., Czelusniak, J., Suzuki, T., Gotoh, T., Moens, L., Shishikura, F., Walz, D., and Vinogradov, S. (1988) J. Mol. Evol. 27, 236-249 |
| 26. | Forstner, M., Kriechbaum, M., Laggner, P., and Wallimann, T. (1996) J. Mol. Struct. 383, 217-227 |
| 27. | Forstner, M., Kriechbaum, M., Laggner, P., and Wallimann, T. (1998) Biophys. J. 75, 1016-1023 |
| 28. | Zhou, G., Ellington, W. R., and Chapman, M. S. (2000) Biophys. J. 78, 1541-1550 |
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  A. Azzi, S. A. Clark, W. R. Ellington, and M. S. Chapman The role of phosphagen specificity loops in arginine kinase Protein Sci., March 1, 2004; 13(3): 575 - 585. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. M. Compaan and W. R. Ellington Functional consequences of a gene duplication and fusion event in an arginine kinase J. Exp. Biol., May 1, 2003; 206(9): 1545 - 1556. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |
