Transcriptional activation of the mrkA promoter of the Klebsiella pneumoniae type 3 fimbrial operon by the c-di-GMP-dependent MrkH protein.

ABSTRACT: The Gram-negative bacterial pathogen Klebsiella pneumoniae forms biofilms to facilitate colonization of biotic and abiotic surfaces. The formation of biofilms by K. pneumoniae requires the expression of type 3 fimbriae: elongate proteinaceous filaments extruded by a chaperone-usher system in the bacterial outer membrane. The expression of the mrkABCDF cluster that encodes this fimbrial system is strongly positively regulated by MrkH, a transcriptional activator that responds to the second messenger, c-di-GMP. In this study, we analyzed the mechanism by which the MrkH protein activates transcriptional initiation from the mrkA promoter. A mutational analysis supported by electrophoretic mobility shift assays demonstrated that a 12-bp palindromic sequence (the MrkH box) centered at -78.5 is t

SUBMITTER: Yang J 

PROVIDER: S-EPMC3828302 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature