1XJM

Structural mechanism of allosteric substrate specificity in a ribonucleotide reductase: dTTP complex

1XJM の概要

• エントリーDOI: 10.2210/pdb1xjm/pdb
• 関連するPDBエントリー: 1XJE 1XJF 1XJG 1XJJ 1XJK 1XJN
• 分子名称: ribonucleotide reductase, B12-dependent, MAGNESIUM ION, THYMIDINE-5'-TRIPHOSPHATE, ... (4 entities in total)
• 機能のキーワード: ribonucleotide reductase, 10 alpha-beta barrel, allosteric regulation, substrate specificity, protein-nucleotide complex, oxidoreductase
• 由来する生物種: Thermotoga maritima
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 148725.75

構造登録者

Larsson, K.-M.,Jordan, A.,Eliasson, R.,Reichard, P.,Logan, D.T.,Nordlund, P. (登録日: 2004-09-23, 公開日: 2005-12-20, 最終更新日: 2023-08-23)

主引用文献

Larsson, K.-M.,Jordan, A.,Eliasson, R.,Reichard, P.,Logan, D.T.,Nordlund, P.
Structural mechanism of allosteric substrate specificity regulation in a ribonucleotide reductase.
Nat.Struct.Mol.Biol., 11:1142-1149, 2004

PubMed Abstract: Ribonucleotide reductases (RNRs) catalyze the reduction of ribonucleotides into deoxyribonucleotides, which constitute the precursor pools used for DNA synthesis and repair. Imbalances in these pools increase mutational rates and are detrimental to the cell. Balanced precursor pools are maintained primarily through the regulation of the RNR substrate specificity. Here, the molecular mechanism of the allosteric substrate specificity regulation is revealed through the structures of a dimeric coenzyme B12-dependent RNR from Thermotoga maritima, both in complexes with four effector-substrate nucleotide pairs and in three complexes with only effector. The mechanism is based on the flexibility of loop 2, a key structural element, which forms a bridge between the specificity effector and substrate nucleotides. Substrate specificity is achieved as different effectors and their cognate substrates stabilize specific discrete loop 2 conformations. The mechanism of substrate specificity regulation is probably general for most class I and class II RNRs.

PubMed: 15475969
DOI: 10.1038/nsmb838

実験手法

X-RAY DIFFRACTION (2.4 Å)