Mutation at the "exit gate" of the salmonella gyrase a subunit suppresses a defect in the gyrase B subunit.

ABSTRACT: In Salmonella enterica serovar Typhimurium, an S431P substitution in the B subunit of gyrase (allele gyrB651) confers resistance to nalidixic acid and causes reduced DNA superhelicity and hypersensitivity to novobiocin. Selection for novobiocin resistance allowed isolation of a mutation in the gyrA gene (allele gyrA659), a T467S substitution, which partially suppresses the supercoiling defect of gyrB651. Modeling analysis suggests that this mutation acts by destabilizing the GyrA bottom dimer interface. This is the first example of a gyrA mutation that compensates for a gyrB defect.

SUBMITTER: Blanc-Potard AB 

PROVIDER: S-EPMC1251596 | biostudies-literature | 2005 Oct

REPOSITORIES: biostudies-literature