HMM Summary Page: TIGR02506

Functionribonucleoside-diphosphate reductase, alpha subunit
Trusted Cutoff341.05
Domain Trusted Cutoff341.05
Noise Cutoff319.00
Domain Noise Cutoff319.00
Isology Typeequivalog
EC Number1.17.4.1
HMM Length616
Mainrole CategoryPurines, pyrimidines, nucleosides, and nucleotides
Subrole Category2'-Deoxyribonucleotide metabolism
Gene Ontology TermGO:0005971: ribonucleoside-diphosphate reductase complex cellular_component
GO:0009265: 2'-deoxyribonucleotide biosynthetic process biological_process
GO:0016959: class I ribonucleotide reductase activity molecular_function
AuthorSelengut J
Entry DateMar 7 2005 1:54PM
Last ModifiedFeb 14 2011 3:27PM
CommentThis model represents the alpha (large) chain of the class I ribonucleotide reductase (RNR). RNR's are responsible for the conversion of the ribose sugar of RNA into the deoxyribose sugar of DNA. This is the rate-limiting step of DNA biosynthesis. Class I RNR's generate the required radical (on tyrosine) via a "non-heme" iron cofactor which resides in the beta (small) subunit. The alpha subunit contains the catalytic and allosteric regulatory sites. The mechanism of this enzyme requires molecular oxygen [1]. E. Coli contains two versions of this enzyme which are regulated independently (NrdAB and NrdEF, where NrdA and NrdE are the large chains [2,3]). Most organisms contain only one, but the application of the gene symbols NrdA and NrdE are somewhat arbitrary. This model identifies RNR's in diverse clades of bacteria, eukaryotes as well as numerous DNA viruses and phage.
ReferencesCC CC RN [1] RM PMID: 11807048 RT Aerobic-type ribonucleotide reductase in the anaerobe Bacteroides fragilis. RA Smalley D, Rocha ER, Smith CJ. RL J Bacteriol. 2002 Feb;184(4):895-903. RN [2] RM PMID: 8052308 RT Structure of ribonucleotide reductase protein R1. RA Uhlin U, Eklund H. RL Nature. 1994 Aug 18;370(6490):533-9. RN [3] RM PMID: 8820648 RT Promoter identification and expression analysis of Salmonella typhimurium and Escherichia coli nrdEF operons encoding one of two class I ribonucleotide reductases present in both bacteria. RA Jordan A, Aragall E, Gibert I, Barbe J. RL Mol Microbiol. 1996 Feb;19(4):777-90.
Genome PropertyGenProp0289: class I (aerobic) ribonucleotide reductase (HMM)