Kinase activity of overexpressed HipA is required for growth arrest and multidrug tolerance in Escherichia coli.

ABSTRACT: Overexpression of the HipA protein of the HipBA toxin/antitoxin module leads to multidrug tolerance in Escherichia coli. HipA is a "toxin" that causes reversible dormancy, whereas HipB is an antitoxin that binds HipA and acts as a transcriptional repressor of the hipBA operon. Comparative sequence analysis shows that HipA is a member of the phosphatidylinositol 3/4-kinase superfamily. The kinase activity of HipA was examined. HipA was autophosphorylated in the presence of ATP in vitro, and the purified protein appeared to carry a single phosphate group on serine 150. Thus, HipA is a serine kinase that is at least partially phosphorylated in vivo. Overexpression of HipA caused inhibition of cell growth and increase in persister formation. Replacing conserved aspartate 309 in the conserved k

SUBMITTER: Correia FF 

PROVIDER: S-EPMC1698217 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature