Dual involvement of CbrAB and NtrBC in the regulation of histidine utilization in Pseudomonas fluorescens SBW25.

ABSTRACT: Pseudomonas fluorescens SBW25 is capable of growing on histidine as a sole source of carbon and/or nitrogen. Previous work showed that the two-component regulatory system CbrAB is required for expression of the histidine utilization (hut) locus when histidine is the sole source of carbon and nitrogen. Here, using mutational analysis and transcriptional assays, we demonstrate involvement of a second two-component system, NtrBC. When histidine is the sole carbon source, transcription of the hutU operon is initiated from a sigma54-type promoter and requires CbrB (an enhancer binding protein for sigma54-recruitment). However, when histidine is the sole nitrogen source, the hutU operon is transcribed from a sigma70-type promoter and requires either CbrB or the nitrogen regulator, NtrC. No role

SUBMITTER: Zhang XX 

PROVIDER: S-EPMC2206070 | biostudies-literature | 2008 Jan

REPOSITORIES: biostudies-literature