title: Cloning and characterization of the xyl genes from Escherichia coli.
abstract: Specific xylose utilization mutants of Escherichia coli were isolated that had altered xylose isomerase ( xylA ), xylulokinase ( xylB ), and regulatory ( xylR ) or transport ( xylT ) activities. We screened the Clarke and Carbon E. coli gene bank and one clone, pLC10 -15, was found to complement the xyl mutants we had characterized. Subcloning and DNA restriction mapping allowed us to locate the xylA and xylB genes on a 1.6 kbp Bg/II fragment and a 2.6 kbp HindIII-Sa/I fragment, respectively. The identification and mapping of xyl gene promoters suggest that the xylA and xylB genes are organized as an operon having a single xylose inducible promoter preceding the xylA gene.
mesh_terms: D019747:Aldose-Ketose Isomerases; D001426:Bacterial Proteins / Q000235:genetics*; D002238:Carbohydrate Epimerases / Q000235:genetics*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005796:Genes; D005798:Genes, Bacterial; D005809:Genes, Regulator; D009876:Operon; D010770:Phosphotransferases / Q000235:genetics*; D017853:Phosphotransferases (Alcohol Group Acceptor); D014994:Xylose / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D014994:Xylose; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C032700:xylulokinase; D002238:Carbohydrate Epimerases; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase