Metal-specific control of gene expression mediated by Bradyrhizobium japonicum Mur and Escherichia coli Fur is determined by the cellular context.

ABSTRACT: Bradyrhizobium japonicum Mur and Escherichia coli Fur are manganese- and iron-responsive transcriptional regulators, respectively, that belong to the same protein family. Here, we show that neither Mur nor Fur discriminate between Fe(2+) and Mn(2+) in vitro nor is there a metal preference for conferral of DNA-binding activity on the purified proteins. When expressed in E. coli, B. japonicum Mur responded to iron, but not manganese, as determined by in vivo promoter occupancy and transcriptional repression activity. Moreover, E. coli Fur activity was manganese-dependent in B. japonicum. Total and chelatable iron levels were higher in E. coli than in B. japonicum under identical growth conditions, and Mur responded to iron in a B. japonicum iron export mutant that accumulated high levels of

SUBMITTER: Hohle TH 

PROVIDER: S-EPMC4925281 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature