From Proteopedia

p53R2

spinqualitylabelsall models PDB ID 3hf1 Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
3hf1, resolution 2.60Å ()
Ligands:	,
Gene:	RRM2B, P53R2 (Homo sapiens)
Activity:	Ribonucleoside-diphosphate reductase, with EC number 1.17.4.1
Related:	1xsm, 2uw2, 1w69, 1w68
Structural annotation: Resources: InterPro : Ipr000358, Ipr009078, Ipr012348 Pfam : PF00268
Evolutionary conservation: Further Information: Caveats, Explanation, Complete Results at ConSurfDB
Resources:	FirstGlance, OCA, RCSB, PDBsum
Coordinates:	save as pdb, mmCIF, xml

P53R2 is an oxydoreductase composed of 351 residues. It is a small subunit of the ribonucleotide reductase (RNR). RNR catalyses the reduction of the four nucleotides to desoxyribonucleotides. It exists three classes of RNR. Class I RNR is a tetramer composed of the two types of subunits with stoichiometry α2β2 and three subunits have been identified in mammals : - Large (α) subunit M1 that contains the enzyme active site - Small (β) subunit M2 that contains a dinuclear iron site, it’s the regulatory subunit - P53R2, the last identified (in 2000), which is transactivated by p53 in response to DNA damage in cells during the G0-G1 cell cycle phase M2 and p53R2 interact with M1 through the C-terminal binding domain. These two subunits share more than 80% sequence identity. But the few differences between the two are not unimportant, as it’s explained below. The first X-ray crystal structure of p53R2 has a resolution of 2,6 Å and permits to describe its structure and also to show the structural differences with the M2 subunit.

Structure and function