title: Genetic regulatory mechanisms and the ecological niche of Escherichia coli.
abstract: Whether the regulatory protein of an inducible operon for a catabolic pathway is a positive or a negative element in the control of expression is correlated with the frequent or infrequent presence, respectively, of the system's substrate in the natural environment.
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis*; D005075:Biological Evolution; D006224:Cricetinae; D004926:Escherichia coli / Q000378:metabolism*; D005809:Genes, Regulator; D007408:Intestinal Absorption; D007785:Lactose / Q000378:metabolism; D008320:Maltose / Q000378:metabolism; D008954:Models, Biological; D009005:Monosaccharides / Q000378:metabolism; D009154:Mutation; D009876:Operon
chemical_list: D001426:Bacterial Proteins; D009005:Monosaccharides; D008320:Maltose; D007785:Lactose