4TWZ
Crystal Structure Analysis of E Coli. RecA Protein
Summary for 4TWZ
| Entry DOI | 10.2210/pdb4twz/pdb |
| Descriptor | Protein RecA, MAGNESIUM ION (3 entities in total) |
| Functional Keywords | homologous recombination, dna binding, recombination |
| Biological source | Escherichia coli K12 |
| Total number of polymer chains | 1 |
| Total formula weight | 37909.39 |
| Authors | Hikima, T.,Hiraki, T.,Furuse, M.,Ikawa, S.,Iwasaki, W.,Shibata, T.,Kamiya, N. (deposition date: 2014-07-02, release date: 2015-07-08, Last modification date: 2024-03-20) |
| Primary citation | 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 Cited by 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: 25561575DOI: 10.1093/nar/gku1364 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.8 Å) |
Structure validation
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