4TWZ

Crystal Structure Analysis of E Coli. RecA Protein

4TWZ の概要

• エントリーDOI: 10.2210/pdb4twz/pdb
• 分子名称: Protein RecA, MAGNESIUM ION (3 entities in total)
• 機能のキーワード: homologous recombination, dna binding, recombination
• 由来する生物種: Escherichia coli K12
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 37909.39

構造登録者

Hikima, T.,Hiraki, T.,Furuse, M.,Ikawa, S.,Iwasaki, W.,Shibata, T.,Kamiya, N. (登録日: 2014-07-02, 公開日: 2015-07-08, 最終更新日: 2024-03-20)

主引用文献

Shinohara, T.,Ikawa, S.,Iwasaki, W.,Hiraki, T.,Hikima, T.,Mikawa, T.,Arai, N.,Kamiya, N.,Shibata, T.
Loop L1 governs the DNA-binding specificity and order for RecA-catalyzed reactions in homologous recombination and DNA repair
Nucleic Acids Res., 43:973-986, 2015

PubMed Abstract: In all organisms, RecA-family recombinases catalyze homologous joint formation in homologous genetic recombination, which is essential for genome stability and diversification. In homologous joint formation, ATP-bound RecA/Rad51-recombinases first bind single-stranded DNA at its primary site and then interact with double-stranded DNA at another site. The underlying reason and the regulatory mechanism for this conserved binding order remain unknown. A comparison of the loop L1 structures in a DNA-free RecA crystal that we originally determined and in the reported DNA-bound active RecA crystals suggested that the aspartate at position 161 in loop L1 in DNA-free RecA prevented double-stranded, but not single-stranded, DNA-binding to the primary site. This was confirmed by the effects of the Ala-replacement of Asp-161 (D161A), analyzed directly by gel-mobility shift assays and indirectly by DNA-dependent ATPase activity and SOS repressor cleavage. When RecA/Rad51-recombinases interact with double-stranded DNA before single-stranded DNA, homologous joint-formation is suppressed, likely by forming a dead-end product. We found that the D161A-replacement reduced this suppression, probably by allowing double-stranded DNA to bind preferentially and reversibly to the primary site. Thus, Asp-161 in the flexible loop L1 of wild-type RecA determines the preference for single-stranded DNA-binding to the primary site and regulates the DNA-binding order in RecA-catalyzed recombinase reactions.

PubMed: 25561575
DOI: 10.1093/nar/gku1364

実験手法

X-RAY DIFFRACTION (2.8 Å)