Gene Ontology Help

Ribonucleoside-diphosphate reductase variant 1 Overview

GO Annotations consist of four mandatory components: a gene product, a term from one of the three Gene Ontology (GO) controlled vocabularies (Molecular Function, Biological Process, and Cellular Component), a reference, and an evidence code.


Summary
Catalyzes the reduction of ribonucleotides to the corresponding deoxyribonucleotides, an essential step in the de novo synthesis of monomeric precursors for DNA replication and repair. The catalytically active form is an alpha2beta2 tetramer. The homodimeric alpha subunit, called R1, houses the active site, composed of redox-active disulfides, and binding sites for allosteric effectors, ribonucleoside diphosphates. The beta subunit, called R2, contains a di-iron cluster that in its reduced state reacts with dioxygen to form a stable tyrosyl radical (Y*) and a di-iron(III) cluster. This essential Y* is proposed to generate a thiyl radical, located on a cysteine residue in the R1 active site, that initiates ribonucleotide reduction. The enzyme is allosterically controlled by relative levels of dNTPs. This variant is found in all cell states, a related variant (CPX-1103) is only found in damaged or growth-arrested cells. the small subunit, RNR2-RNR4, is nuclear while the large subunit, RNR1, is cytoplasmic. In response to S-phase or DNA-damage, RNR2-RNR4 enters the cytoplasm to bind RNR1.
GO Slim Terms

The yeast GO Slim terms are higher level terms that best represent the major S. cerevisiae biological processes, functions, and cellular components. The GO Slim terms listed here are the broader parent terms for the specific terms to which this gene product is annotated, and thus represent the more general processes, functions, and components in which it is involved.

ion binding, oxidoreductase activity, biosynthetic process, cellular nitrogen compound metabolic process, nucleobase-containing small molecule metabolic process, small molecule metabolic process, cytoplasm, ribonucleoside-diphosphate reductase complex