Rosenfeld S A, Stevis P E, Ho N W
Mol Gen Genet. 1984;194(3):410-5. doi: 10.1007/BF00425552.
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.
分离出了大肠杆菌的特定木糖利用突变体，这些突变体的木糖异构酶（xylA）、木酮糖激酶（xylB）以及调节（xylR）或转运（xylT）活性发生了改变。我们筛选了克拉克和卡尔文的大肠杆菌基因文库，发现一个克隆体pLC10 - 15能够互补我们已鉴定的木糖突变体。亚克隆和DNA限制性图谱分析使我们能够分别将xylA和xylB基因定位在一个1.6千碱基对的Bg/II片段和一个2.6千碱基对的HindIII - Sa/I片段上。木糖基因启动子的鉴定和图谱分析表明，xylA和xylB基因组织成一个操纵子，在xylA基因之前有一个单一的木糖诱导型启动子。
