title: The mechanism of sugar-mediated catabolite repression of the propionate catabolic genes in Escherichia coli.
abstract: Carbon catabolite repression (CCR) is a well-known phenomenon that involves the preferential utilization of glucose as a carbon source. Cyclic adenosine monophosphate (cAMP) and the cAMP receptor protein (CRP) mediate CCR. Recently, a second CCR hierarchy that leads to the preferential consumption of arabinose over xylose, mediated by arabinose-bound AraC, has been identified. In this study, we report yet another CCR hierarchy that causes the preferential utilization of sugars (arabinose, galactose, glucose, mannose, and xylose) over a short-chain fatty acid (propionate). Expression of the propionate catabolic (prpBCDE) genes is down-regulated in the presence of these sugars. Sugar-mediated repression of the propionate catabolic genes is independent of sugar-specific regulators such as AraC and dependent on global regulators of sugar transport such as the cAMP-CRP complex and the Phosphotransferase System (PTS). Inhibition of the prpBCDE promoter is encountered during rapid sugar uptake and metabolism. This unique regulatory crosstalk between sugar metabolism and fatty acid metabolism may help provide new insights into CRP-dependent catabolite repression acting in conjunction with non-carbohydrate metabolism.
authors.affiliation: School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Park
authors.forename: Parisutham
authors.initials: P
authors.lastname: Vinuselvi
authors.forename: Sung Kuk
authors.initials: SK
authors.lastname: Lee
mesh_terms: D050260:Carbohydrate Metabolism; D002244:Carbon / Q000378:metabolism; D057465:Catabolite Repression; D003066:Coenzyme A Ligases / Q000235:genetics*; D000242:Cyclic AMP / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D020868:Gene Silencing; D005947:Glucose / Q000378:metabolism*; D011422:Propionates / Q000378:metabolism*
chemical_list: D011422:Propionates; D002244:Carbon; D000242:Cyclic AMP; D003066:Coenzyme A Ligases; C068072:propionate - CoA ligase; D005947:Glucose