Proline Utilization by Bacillus subtilis: Uptake and Catabolism

• DOI: 10.1128/jb.06380-11
• Publication Date: 2011-12-03T20:25:32Z
• Authors: Susanne Moses; Tatjana Sinner; Adrienne Zaprasis; Nadine Stöveken; Tamara Hoffmann; Boris R. Belitsky; Abraham L. Sonens...; Erhard Bremer
• Keywords: Proline dehydrogenase; Transcription

ABSTRACT l -Proline can be used by Bacillus subtilis as a sole source of carbon or nitrogen. We traced -proline utilization genetically to the putBCP ( ycgMNO ) locus. The gene cluster encodes high-affinity proline transporter (PutP) and two enzymes, dehydrogenase PutB Δ 1 -pyrroline-5-carboxylate PutC, which jointly catabolize -glutamate. Northern blotting, primer extension, putB-treA reporter fusion analysis showed that locus is transcribed an -proline-inducible operon. Its expression was mediated SigA-type promoter dependent on proline-responsive PutR activator protein. Induction triggered presence submillimolar concentrations in growth medium. However, very large quantities (up several hundred millimolar) synthesized B. stress protectant against high osmolarity did not induce transcription. transcription external uptake via substrate-inducible PutP osmotically inducible OpuE transporter. It also chemoreceptor protein McpC required for chemotaxis toward -proline. Our findings imply distinguish externally supplied from internal pools generated through de novo synthesis. molecular basis this regulatory phenomenon understood. it provides cell with means avoid futile cycle synthesis consumption triggering catabolic genes response osmoadaptive production compatible solute