title: DNA-binding surface of RecA protein photochemical cross-linking of the first DNA binding site on RecA filament.
abstract: The first DNA-binding site (site I) of RecA protein on the filament has been mapped. RecA protein was covalently cross-linked with a 55-base synthetic single-stranded DNA which was a good substrate for the RecA-mediated strand exchange reaction. The cross-linking sites of protein were determined in the regions spanning RecA residues 64-68, 89-106, 178-183, 199-216 and 257-280. The cross-linking in the residues 64-68, 89-106, 199-216 and 257-280 would be due to the cross-linking of Tyr65, Tyr103, disordered loop 2, and Tyr264, respectively. These regions form a DNA-binding surface centered around the beta-sheet spanning residues 243-257. In the P6(1) crystal filament, the DNA-binding surface is near the RecA-RecA interface but are not in the filament axis. The data implicate a mechanism whereby the DNA binding surface would be led into the filament axis by a conformational change from inactive filament as the P6(1) structure to active filament as the RecA-DNA-ATP complex.
authors.affiliation: Department of Molecular Protozoology, Osaka University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Morimatsu
authors.forename: T
authors.initials: T
authors.lastname: Horii
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D002852:Chromatography, Ion Exchange; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010449:Peptide Mapping; D010777:Photochemistry; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011938:Rec A Recombinases / Q000737:chemistry* / Q000378:metabolism; D017421:Sequence Analysis; D014466:Ultraviolet Rays
chemical_list: D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D010446:Peptide Fragments; C022571:adenosine 5'-O-(3-thiotriphosphate); D000255:Adenosine Triphosphate; D011938:Rec A Recombinases; D010450:Endopeptidases