Dahl M K, Schmiedel D, Hillen W
Lehrstuhl für Mikrobiologie, Biochemie und Genetik der Friedrich-Alexander Universität Erlangen-Nürnberg, Germany.
J Bacteriol. 1995 Oct;177(19):5467-72. doi: 10.1128/jb.177.19.5467-5472.1995.
The xyl operons of several gram-positive bacteria are regulated at the level of transcription by xylose-responsive repressor proteins (XylR). In addition, they are catabolite repressed. Here, we describe a mechanism by which glucose metabolism can affect both regulatory mechanisms. Glucose-6-phosphate appeared to be an anti-inducer of xyl operon transcription, since it could compete with xylose in interaction in vitro with XylR from Bacillus subtilis, B. megaterium, and B. licheniformis. On the other hand, glucose was a low-efficiency inactivator of XylR from B. subtilis and B. megaterium and a weak anti-inducer of XylR from B. licheniformis. Thus, the chemical nature of the substituent at C-5 of xylose and the primary structure of XylR determine the effect of these compounds on xyl operon transcription.
几种革兰氏阳性菌的木糖操纵子在转录水平上受木糖响应阻遏蛋白（XylR）调控。此外，它们还受到分解代谢物阻遏。在此，我们描述了一种葡萄糖代谢可影响这两种调控机制的机制。6-磷酸葡萄糖似乎是木糖操纵子转录的抗诱导剂，因为它在体外与枯草芽孢杆菌、巨大芽孢杆菌和地衣芽孢杆菌的XylR相互作用时能与木糖竞争。另一方面，葡萄糖是枯草芽孢杆菌和巨大芽孢杆菌XylR的低效失活剂，是地衣芽孢杆菌XylR的弱抗诱导剂。因此，木糖C-5位取代基的化学性质和XylR的一级结构决定了这些化合物对木糖操纵子转录的影响。
