Petukhov Michael, Lebedev Dmitry, Shalguev Valery, Islamov Akhmed, Kuklin Aleksandr, Lanzov Vladislav, Isaev-Ivanov Vladimir
Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, the Russian Academy of Sciences, Gatchina/St. Petersburg, Russia.
Proteins. 2006 Nov 1;65(2):296-304. doi: 10.1002/prot.21116.
RecA protein is a central enzyme in homologous DNA recombination, repair and other forms of DNA metabolism in bacteria. It functions as a flexible helix-shaped filament bound on stretched single-stranded or double-stranded DNA in the presence of ATP. In this work, we present an atomic level model for conformational transitions of the RecA filament. The model describes small movements of the RecA N-terminal domain due to coordinated rotation of main chain dihedral angles of two amino acid residues (Psi/Lys23 and Phi/Gly24), while maintaining unchanged the RecA intersubunit interface. The model is able to reproduce a wide range of observed helix pitches in transitions between compressed and stretched conformations of the RecA filament. Predictions of the model are in agreement with Small Angle Neutron Scattering (SANS) measurements of the filament helix pitch in RecA::ADP-AlF(4) complex at various salt concentrations.
RecA蛋白是细菌中同源DNA重组、修复及其他形式DNA代谢过程中的核心酶。在ATP存在的情况下，它作为一种柔性螺旋状细丝结合在伸展的单链或双链DNA上。在这项工作中，我们提出了RecA细丝构象转变的原子水平模型。该模型描述了由于两个氨基酸残基（Psi/Lys23和Phi/Gly24）主链二面角的协同旋转导致的RecA N端结构域的微小移动，同时RecA亚基间界面保持不变。该模型能够再现RecA细丝在压缩和伸展构象转变过程中观察到的广泛螺旋间距。该模型的预测结果与不同盐浓度下RecA::ADP-AlF(4)复合物中细丝螺旋间距的小角中子散射（SANS）测量结果一致。
