Open AccessMutation at the “Exit Gate” of the Salmonella Gyrase A Subunit Suppresses a Defect in the Gyrase B Subunit
Author(s) -
AnneBéatrice BlancPotard,
Gilles Labesse,
Nara FigueroaBossi,
Lionello Bossi
Publication year - 2005
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.187.19.6841-6844.2005
Subject(s) - dna gyrase , novobiocin , nalidixic acid , biology , salmonella enterica , mutation , protein subunit , genetics , dna supercoil , salmonella , gene , microbiology and biotechnology , escherichia coli , bacteria , dna replication
InSalmonella enterica serovar Typhimurium, an S431P substitution in the B subunit of gyrase (allelegyrB651 ) confers resistance to nalidixic acid and causes reduced DNA superhelicity and hypersensitivity to novobiocin. Selection for novobiocin resistance allowed isolation of a mutation in thegyrA gene (allelegyrA659 ), a T467S substitution, which partially suppresses the supercoiling defect ofgyrB651 . Modeling analysis suggests that this mutation acts by destabilizing the GyrA bottom dimer interface. This is the first example of agyrA mutation that compensates for agyrB defect.