HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fieschi, F. Articles by Sjöberg, B.-M. Search for Related Content PubMed PubMed Citation Articles by Fieschi, F. Articles by Sjöberg, B.-M. Social Bookmarking                      What's this?

J Biol Chem, Vol. 273, Issue 8, 4329-4337, February 20, 1998

The Manganese-containing Ribonucleotide Reductase of Corynebacterium ammoniagenes Is a Class Ib Enzyme

Franck Fieschi, Eduard Torrents, Larisa Toulokhonova, Albert Jordan, Ulf Hellman^§§, Jordi Barbe, Isidre Gibert, Margareta Karlsson, and Britt-Marie Sjöberg

From the  Department of Molecular Biology, Stockholm University, S-106 91 Stockholm, Sweden, the  Department of Genetics & Microbiology, Faculty of Sciences, Autonomous University of Barcelona, Bellaterra, 08193 Barcelona, Spain, and the ^§§ Ludwig Institute for Cancer Research, Biomedical Center, Box 595, S-751 24 Uppsala, Sweden

Ribonucleotide reductases (RNRs) are key enzymes in living cells that provide the precursors of DNA synthesis. The three characterized classes of RNRs differ by their metal cofactor and their stable organic radical. We have purified to near homogeneity the enzymatically active Mn-containing RNR of Corynebacterium ammoniagenes, previously claimed to represent a fourth RNR class. N-terminal and internal peptide sequence analyses clearly indicate that the C. ammoniagenes RNR is a class Ib enzyme. In parallel, we have cloned a 10-kilobase pair fragment from C. ammoniagenes genomic DNA, using primers specific for the known class Ib RNR. The cloned class Ib locus contains the nrdHIEF genes typical for class Ib RNR operon. The deduced amino acid sequences of the nrdE and nrdF genes matched the peptides from the active enzyme, demonstrating that C. ammoniagenes RNR is composed of R1E and R2F components typical of class Ib. We also show that the Mn-containing RNR has a specificity for the NrdH-redoxin and a response to allosteric effectors that are typical of class Ib RNRs. Electron paramagnetic resonance and atomic absorption analyses confirm the presence of Mn as a cofactor and show, for the first time, insignificant amounts of iron and cobalt found in the other classes of RNR. Our discovery that C. ammoniagenes RNR is a class Ib enzyme and possesses all the highly conserved amino acid side chains that are known to ligate two ferric ions in other class I RNRs evokes new, challenging questions about the control of the metal site specificity in RNR. The cloning of the entire NrdHIEF locus of C. ammoniagenes will facilitate further studies along these lines.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				I. Roca, E. Torrents, M. Sahlin, I. Gibert, and B.-M. Sjoberg NrdI Essentiality for Class Ib Ribonucleotide Reduction in Streptococcus pyogenes J. Bacteriol., July 15, 2008; 190(14): 4849 - 4858. [Abstract] [Full Text] [PDF]

				E. Torrents, M. Sahlin, D. Biglino, A. Graslund, and B.-M. Sjoberg Efficient growth inhibition of Bacillus anthracis by knocking out the ribonucleotide reductase tyrosyl radical PNAS, December 13, 2005; 102(50): 17946 - 17951. [Abstract] [Full Text] [PDF]

				H. M. Elhariry, J. Meens, M. Stehr, and G. Auling S434F in NrdE Generates the Thermosensitive Phenotype of Corynebacterium ammoniagenes CH31 and Enhances Thermolability by Increasing the Surface Hydrophobicity of the NrdE(Ts) Protein Appl. Envir. Microbiol., September 1, 2005; 71(9): 5582 - 5586. [Abstract] [Full Text] [PDF]

				E. Torrents, I. Roca, and I. Gibert Corynebacterium ammoniagenes class Ib ribonucleotide reductase: transcriptional regulation of an atypical genomic organization in the nrd cluster Microbiology, April 1, 2003; 149(4): 1011 - 1020. [Abstract] [Full Text] [PDF]

				I. Borovok, R. Kreisberg-Zakarin, M. Yanko, R. Schreiber, M. Myslovati, F. Aslund, A. Holmgren, G. Cohen, and Y. Aharonowitz Streptomyces spp. contain class Ia and class II ribonucleotide reductases: expression analysis of the genes in vegetative growth Microbiology, February 1, 2002; 148(2): 391 - 404. [Abstract] [Full Text] [PDF]

				A. Jordan, E. Torrents, I. Sala, U. Hellman, I. Gibert, and P. Reichard Ribonucleotide Reduction in Pseudomonas Species: Simultaneous Presence of Active Enzymes from Different Classes J. Bacteriol., July 1, 1999; 181(13): 3974 - 3980. [Abstract] [Full Text]

				Y. Huque, F. Fieschi, E. Torrents, I. Gibert, R. Eliasson, P. Reichard, M. Sahlin, and B.-M. Sjoberg The Active Form of the R2F Protein of Class Ib Ribonucleotide Reductase from Corynebacterium ammoniagenes Is a Diferric Protein J. Biol. Chem., August 11, 2000; 275(33): 25365 - 25371. [Abstract] [Full Text] [PDF]