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ribonucleotide reductase B1 subunit; M1 subunit; ribonucleoside diphosphate reductase large subunit (RRM1, RR1)
Function:
- provides precursors for DNA synthesis
- catalyzes biosynthesis of deoxyribonucleotides from the corresponding ribonucleotides
- under complex allosteric control mediated by binding of deoxynucleoside triphosphates & ATP to binding sites on the M1 subunit
- ribonucleotide reductase is a heterodimer of a large (M1) & a small chain (M2)
- interacts with RRM2B
- Genetic information processing, DNA replication
- 2 distinct regulatory sites have been defined:
a) the specificity site, which controls substrate specificity,
b) activity site which regulates overall catalytic activity
- substrate-binding catalytic site, located on M1, is formed only in the presence of the 2nd subunit M2
2'-deoxyribonucleoside diphosphate + thioredoxin disulfide + H2O
ribonucleoside diphosphate + thioredoxin
Structure:
- belongs to the ribonucleoside diphosphate reductase large chain family
- contains 1 ATP-cone domain
Compartment: cytoplasm
Expression:
- level of the enzyme activity is closely correlated with the growth rate of a cell & appears to vary with the cell cycle
Pathology:
- ribonucleotide reductase is thought to mediate pathogenesis of the immunodeficiency of
a) adenosine deaminase deficiency
b) purine nucleoside phosphorylase deficiency
- the deoxynucleotides that accumulate in the lymphoid cells of these patients are thought to feed-back inhibit ribonucleotide reductase, preventing DNA replication & cell proliferation
General
oligomerizing protein
protein subunit
Properties
SIZE: entity length = 792 aa
MW = 90 kD
COMPARTMENT: cytoplasm
MOTIF: ATP-cone {1-92}
cysteine residue {C218}
Allosteric effector binding {226-226}
Allosteric effector binding {256-256}
asparagine residue {N427}
cysteine residue {C429}
glutamate residue {E431}
cysteine residue {C444}
tyrosine residue {Y737}
tyrosine residue {Y738}
thioredoxin interaction {787-787}
thioredoxin interaction {790-790}
Database Correlations
OMIM 180410
UniProt P23921
PFAM correlations
ENZYME 1.17.4.1
References
- Stryer Biochemistry WH Freeman & Co, New York,
1988 pg 610
- UniProt :accession P23921
- Wikipedia; Note=ribonucleotide reductase entry
http://en.wikipedia.org/wiki/ribonucleotide_reductase
Component-of
ribonucleotide diphosphate reductase