New mutations in and around the L2 disordered loop of the RecA protein modulate recombination and/or coprotease activity.
The RecA protein plays a key role in Escherichia coli recombination and DNA repair. We have created new recA mutants with mutations in the vicinity of the recA430 mutation (Gly-204----Ser) which is known to affect RecA coprotease activity. Mutants carrying recA659 or recA611, located 3 and 7 amino acids downstream of residue 204, respectively, lose all RecA activities, while the mutant carrying recA616, which is located at 12 amino acids from this residue, keeps the coprotease activity but is unable to promote recombination. Complementation experiments show that both mutations recA611 and recA659 are dominant over the wild-type or recA430 allele while recA616 seems to be recessive to recA+ and dominant over recA430. It is suggested that these mutations are located in RecA domains which direct conformational modifications.
Larminat
F
F
Laboratoire de Pharmacologie et de Toxicologie Fondamentales, Centre National de la Recherche Scientifique, Toulouse, France.
Cazaux
C
C
Germanier
M
M
Defais
M
M
D000483:Alleles; D001426:Bacterial Proteins / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000528:radiation effects; D005799:Genes, Dominant / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D011938:Rec A Recombinases / Q000235:genetics* / Q000378:metabolism; D011995:Recombination, Genetic / Q000235:genetics; D013014:SOS Response, Genetics / Q000235:genetics; D012697:Serine Endopeptidases; D013329:Structure-Activity Relationship; D014466:Ultraviolet Rays; D000099160:LexA Repressor Protein
D001426:Bacterial Proteins; D010450:Endopeptidases; D011938:Rec A Recombinases; D012697:Serine Endopeptidases; D000099160:LexA Repressor Protein