Genome Property Definition Page
Accession | GenProp0289 | |
Name | class I (aerobic) ribonucleotide reductase | |
Type | SYSTEM | |
Description | Ribonucleotide reductases (RNRs) 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. The class I RNRs [1] consist of two subunits, alpha and beta (also known as the large and small subunbits, respectively). Class I RNRs generate the required radical (on tyrosine) via a non-heme iron cofactor which resides in the beta subunit. The alpha subunit contains the catalytic and allosteric regulatory sites. The most common gene symbols for these genes are NrdE (alpha) and NrdF (beta), althought the first characterized complex from E.coli (NrdAB) turns out to be one of a pair in gammaproteobacteria and the more divergent one at that. Where multiple class I enzymes exist in a single organism they are presumed to be under differential regulation. Note that earlier reports of a manganese-based class IV system related to class I in high GC gram positive species was proved to be spurious [2]. Electrons for this reduction are supplied by glutaredoxin-like (NrdH, in some species [3]), or flavodoxins specific to this system which are in turn reduced by oxygen via thioredoxin reductase. Detection of this component is not required to set the YES state because of incomplete knowledge of the various homologs involved. Certain class I RNRs are associated with a gene of unknown function (NrdI). NrdI shows up more frequently, but not exclusively in species with more than one class I RNR, so it may be involved in regulation in some way. | |
JCVI Role | 2'-Deoxyribonucleotide metabolism | |
Parent Property | GenProp0287: ribonucleotide reduction | |
Literature References |
| |
Gene Ontology Term | GO:0009265: 2'-deoxyribonucleotide biosynthetic process (biological_process) |
Components
Step Name | Step Num | Required | Evidence (Method) | Evidence Go Terms |
---|---|---|---|---|
aerobic RNR, alpha (large) chain | NrdA/E | YES | TIGR02506 (HMM): ribonucleoside-diphosphate reductase, alpha subunit TIGR02510 (HMM): ribonucleoside-diphosphate reductase, alpha chain | GO:0009265: 2'-deoxyribonucleotide biosynthetic process GO:0009265: 2'-deoxyribonucleotide biosynthetic process |
aerobic RNR, beta (small) chain | NrdB/F | YES | PF00268 (HMM): ribonucleoside-diphosphate reductase, beta subunit | GO:0009265: 2'-deoxyribonucleotide biosynthetic process |
Unknown function | NrdI | NO | TIGR00333 (HMM): nrdI protein | GO:0009265: 2'-deoxyribonucleotide biosynthetic process |
redoxin, ribonucleotide-reductase related | redoxin | NO | TIGR02194 (HMM): glutaredoxin-like protein NrdH TIGR01754 (HMM): putative ribonucleotide reductase-associated flavodoxin | GO:0009265: 2'-deoxyribonucleotide biosynthetic process GO:0009265: 2'-deoxyribonucleotide biosynthetic process |
Parent Properties
Accession | Name |
---|---|
GenProp0287 | ribonucleotide reduction |
Sibling Properties
Accession | Name |
---|---|
GenProp0290 | class II (B12-dependent) ribonucleotide reductase |
GenProp0291 | class III (anaerobic) ribonucleotide reductase |