A rationale for autoinduction of a transcriptional activator: ethanolamine ammonia-lyase (EutBC) and the operon activator (EutR) compete for adenosyl-cobalamin in Salmonella typhimurium

Abstract

The ethanolamine utilization (eut) operon of Salmonella typhimurium is controlled by a positive regulatory protein (EutR) which stimulates eut operon expression in response to the simultaneous presence of two effectors, ethanolamine and adenosyl-cobalamin (Ado-B12). Ado-B12 is a cofactor for ethanolamine ammonialyase (lyase), the first enzyme in the ethanolamine-degradative pathway. The

Localization of Proteins to the 1,2-Propanediol Utilization Microcompartment by Non-native Signal Sequences Is Mediated by a Common Hydrophobic Motif

“…The transcriptional regulator PocR is necessary for Pdu MCP formation (19,(21)(22)(23). We confirmed that the analogous transcriptional regulator EutR is necessary for Eut MCP formation by two methods: first using a fluorescent reporter of P eut transcription (24,25) and then using a fluorescent reporter of encapsulation in the Eut or Pdu MCP (8). We observed activation of the P eut promoter by 30 mM ethanolamine and 150 nM vitamin B 12 as indicated by increased GFP fluorescence in an S. enterica strain containing the P eutgfpmut2 transcriptional reporter as compared with a control culture to which no ethanolamine and vitamin B 12 were added.…”

Identification and in vivo characterization of PpaA, a regulator of photosystem formation in Rhodobacter sphaeroides

“…Interestingly, evidence from R. capsulatus suggests that shown to perform sensory functions, in addition to catalytic functions (Beinert & Kiley, 1999;Christie & Briggs, 2001;Gilles-Gonzalez, 2001;Braatch et al, 2002;Masuda & Bauer, 2002;. Two groups hypothesized that corrinoids might regulate activities of transcription factors (Roof & Roth, 1992;Sheppard & Roth, 1994;Cervantes & Murillo, 2002). The latter report is especially relevant because it considers a possibility that DNA-binding activity of M. xanthus ORF10 (CarA) might be corrinoiddependent.…”

From food to cell: nutrient exploitation strategies of enteropathogens

“…In this bacterium, the availability of cobalamin may be noticed by a riboswitch identified in the untranslated region of the eut operon (Fox et al, 2009). In Salmonella enterica, the eut gene cluster (and also the cob/cbi cluster) are regulated positively by EutR, which is induced by the presence of ethanolamine and cobalamin (Sheppard & Roth, 1994).…”