1QHH

STRUCTURE OF DNA HELICASE WITH ADPNP

1QHH の概要

• エントリーDOI: 10.2210/pdb1qhh/pdb
• 分子名称: PROTEIN (PCRA (SUBUNIT)), ADENOSINE-5'-TRIPHOSPHATE, ... (6 entities in total)
• 機能のキーワード: dna repair, dna replication, sos response, helicase, atp-binding, dna-binding, hydrolase
• 由来する生物種: Geobacillus stearothermophilus; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 83156.24

構造登録者

Soultanas, P.,Dillingham, M.S.,Velankar, S.S.,Wigley, D.B. (登録日: 1999-05-14, 公開日: 1999-07-13, 最終更新日: 2023-12-27)

主引用文献

Soultanas, P.,Dillingham, M.S.,Velankar, S.S.,Wigley, D.B.
DNA binding mediates conformational changes and metal ion coordination in the active site of PcrA helicase.
J.Mol.Biol., 290:137-148, 1999

PubMed Abstract: Based upon the crystal structures of PcrA helicase, we have made and characterised mutations in a number of conserved helicase signature motifs around the ATPase active site. We have also determined structures of complexes of wild-type PcrA with ADPNP and of a mutant PcrA complexed with ADPNP and Mn2+. The kinetic and structural data define roles for a number of different residues in and around the ATP binding site. More importantly, our results also show that there are two functionally distinct conformations of ATP in the active site. In one conformation, ATP is hydrolysed poorly whereas in the other (activated) conformation, ATP is hydrolysed much more rapidly. We propose a mechanism to explain how the stimulation of ATPase activity afforded by binding of single-stranded DNA stabilises the activated conformation favouring Mg2+binding and a consequent repositioning of the gamma-phosphate group which promotes ATP hydrolysis. A part of the associated conformational change in the protein forces the side-chain of K37 to vacate the Mg2+binding site, allowing the cation to bind and interact with ATP.

PubMed: 10388562
DOI: 10.1006/jmbi.1999.2873

実験手法

X-RAY DIFFRACTION (2.5 Å)