JBC Origene Your Gene Company

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gleason, F. K.
Right arrow Articles by Hogenkamp, H. P. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gleason, F. K.
Right arrow Articles by Hogenkamp, H. P. C.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Ribonucleotide Reductase from Euglena gracilis, a Deoxyadenosylcobalamin-dependent Enzyme

F. K. Gleason 1 and H. P. C. Hogenkamp 1

From the 1 From the Department of Biochemistry, College of Medicine, University of Iowa, Iowa City, Iowa 52240

A ribonucleotide reductase requiring 5'-deoxyadenosylcobalamin has been detected in Euglena gracilis var. bacillaris by measuring 3H exchange from labeled coenzyme to water. Extracts were partially purified by centrifugation, dialysis, and treatment with MnCl2. These extracts catalyzed the reduction of ribonucleoside triphosphates to the corresponding deoxyribonucleotides as measured by colorimetric assay with the diphenylamine procedure. The enzyme required 5'-deoxyadenosylcobalamin, a dithiol, and a ribonucleoside triphosphate for exchange activity and reduction. Monothiols could not replace the dithiol requirement. Ribonucleoside diphosphates were slightly active as substrates in both assay systems. Mg++, at low concentrations, did not affect the reaction; at concentrations greater than 2 mm, this ion was inhibitory. The reduction of ribonucleotides was inhibited by adding deoxyribonucleotides other than the immediate products; e.g. ATP reduction was inhibited by adding dGTP, dCTP, or dUTP, but not by dATP. dTTP inhibited the reduction of all ribonucleotides to the greatest extent. The molecular weight of this enzyme, determined by sucrose density gradient centrifugation, was approximately 145,000.

Extracts of Ochromonas malhamensis and Ochromonas danica showed no activity in the 3H exchange assay under similar conditions.

Submitted on April 13, 1970


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
E. Torrents, C. Trevisiol, C. Rotte, U. Hellman, W. Martin, and P. Reichard
Euglena gracilis Ribonucleotide Reductase: THE EUKARYOTE CLASS II ENZYME AND THE POSSIBLE ANTIQUITY OF EUKARYOTE B12 DEPENDENCE
J. Biol. Chem., March 3, 2006; 281(9): 5604 - 5611.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
A. Hofer, P. P. Schmidt, A. Graslund, and L. Thelander
Cloning and characterization of the R1 and R2 subunits of ribonucleotide reductase from Trypanosoma brucei
PNAS, June 24, 1997; 94(13): 6959 - 6964.
[Abstract] [Full Text] [PDF]

Home page
 ScienceHome page
F. Gleason and J. Wood
Ribonucleotide reductase in blue-green algae: dependence on adenosylcobalamin
Science, June 25, 1976; 192(4246): 1343 - 1344.
[Abstract] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 All ASBMB Journals   Molecular and Cellular Proteomics 
 Journal of Lipid Research   ASBMB Today 
Copyright © 1970 by the American Society for Biochemistry and Molecular Biology.