RESUMO
A family of mutants overexpressing the Serratia marcescens extracellular nuclease has been known for decades. A number of these alleles are characterized here at the molecular level, and the mutant genes are identified, yielding a likely model for their phenotype. The known mutations exert their effect indirectly on nucA expression by elevating the basal SOS response of the cell. Mutations have been found in xerC and uvrD, both of which result in partial SOS induction. A classic nucsu allele, that of strain W1050, is also likely to be in xerC.
Assuntos
DNA Helicases , Desoxirribonucleases/genética , Endodesoxirribonucleases/genética , Endorribonucleases/genética , Serratia marcescens/enzimologia , Serratia marcescens/genética , Adenosina Trifosfatases/genética , Alelos , Mapeamento Cromossômico , Elementos de DNA Transponíveis , Endodesoxirribonucleases/biossíntese , Endorribonucleases/biossíntese , Genes Bacterianos , Dados de Sequência Molecular , Mutação , Fases de Leitura Aberta , Fenótipo , Recombinases Rec A/genética , Resposta SOS em GenéticaRESUMO
Proteins synthesized in Escherichia coli during recovery from starvation were resolved by two-dimensional polyacrylamide gel electrophoresis. Nine outgrowth-specific proteins, which appeared in two kinetic groups, that were not detected in either starved or exponential-phase cells were synthesized. Five other proteins whose rate of synthesis during outgrowth was > or = 5-fold higher than during exponential growth were observed.