title: Isolation of altered recA polypeptides and interaction with ATP and DNA.
abstract: In this paper we describe the partial proteolytic digestion of recA proteins from Escherichia coli and Proteus mirabilis and the production and isolation of truncated recA polypeptides. A proteolytic fragment of the P. mirabilis recA protein bound single-strand DNA and ATP normally but has altered duplex DNA binding properties. This protein was shown to initiate but not complete DNA strand transfer from a DNA duplex to a complementary single strand. The product of the E. coli recA1 allele bound but could not hydrolyze ATP and the protein bound single-strand but not double-strand DNA. This protein did not appear to initiate the transfer of a strand from a linear duplex to a single-strand circle and inhibited the wild-type recA protein from performing strand transfer. We report that recA protein binds linear duplex DNA in a manner that enhances the rate of ligation by T4 DNA ligase. When heterologous single-strand DNA was added in addition to the duplex DNA large stable aggregates of protein and DNA were formed that could easily be sedimented from solution.
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism*; D001386:Azides / Q000378:metabolism; D011088:DNA Ligases / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism*; D004926:Escherichia coli; D008970:Molecular Weight; D011513:Proteus mirabilis; D011938:Rec A Recombinases / Q000302:isolation & purification*; D012097:Repressor Proteins / Q000378:metabolism; D013381:Subtilisins / Q000378:metabolism
chemical_list: D001386:Azides; D004277:DNA, Single-Stranded; D004279:DNA, Viral; D012097:Repressor Proteins; C017040:8-azidoadenosine 5'-triphosphate; D000255:Adenosine Triphosphate; D011938:Rec A Recombinases; D013381:Subtilisins; D011088:DNA Ligases