title: Functionally important residues at a subunit interface site in the RecA protein from Escherichia coli.
abstract: Assembly of RecA subunits into long, helical oligomers is required for its roles in recombinational DNA repair and homologous genetic recombination. The crystal structure of RecA reveals an extensive network of amino acid residues that lie at the subunit boundaries. We have introduced a large set of substitutions at 5 clustered residues, which are shown in the crystal structure to make specific contacts with positions in the neighboring monomer. We find that 3 of the 5 residues are important for RecA function (Lys216, Phe217, and Arg222), whereas the other 2 (Asn213 and Tyr218) are not. The patterns of functionally allowed substitutions provide insight into the chemical and steric constraints required at these positions.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Massachusetts Medical Center, Worcester 01655.
authors.forename: M C
authors.initials: MC
authors.lastname: Skiba
authors.forename: K L
authors.initials: KL
authors.lastname: Knight
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004260:DNA Repair; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D005798:Genes, Bacterial; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010957:Plasmids; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011938:Rec A Recombinases / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D011995:Recombination, Genetic; D014466:Ultraviolet Rays
chemical_list: D046911:Macromolecular Substances; D011994:Recombinant Proteins; D011938:Rec A Recombinases