Blanco C, Mata-Gilsinger M, Ritzenthaler P
J Bacteriol. 1983 Feb;153(2):747-55. doi: 10.1128/jb.153.2.747-755.1983.
The uxaB gene of Escherichia coli, encoding for altronate oxidoreductase involved in the hexuronate degradative pathway, was isolated on a ColE1-uxaB hybrid plasmid from the Clarke and Carbon bank. The restriction map of this plasmid was established. The uxaB gene was mapped on a 1.5-megadalton HindIII-KpnI DNA fragment. Use of an in vitro gene fusion between uxaB and lacZ genes led to the determination that uxaB is transcribed from the KpnI towards the HindIII restriction sites. Gene amplification in cells containing various uxaB hybrid plasmids allowed us to show a gradation in the level of repression of exu operator sites by the exuR regulatory gene product.
大肠杆菌的uxaB基因编码参与己糖醛酸降解途径的阿卓糖酸氧化还原酶，该基因是从克拉克和卡本文库的ColE1-uxaB杂种质粒中分离出来的。构建了该质粒的限制性图谱。uxaB基因定位于一个1.5兆道尔顿的HindIII-KpnI DNA片段上。利用uxaB和lacZ基因之间的体外基因融合，确定uxaB是从KpnI朝着HindIII限制性位点转录的。在含有各种uxaB杂种质粒的细胞中进行基因扩增，使我们能够显示exuR调节基因产物对exu操纵子位点的抑制水平存在梯度变化。
