Kreuzer P, Gärtner D, Allmansberger R, Hillen W
Lehrstuhl für Mikrobiologie, Friedrich Alexander Universität Erlangen-Nürnberg, Federal Republic of Germany.
J Bacteriol. 1989 Jul;171(7):3840-5. doi: 10.1128/jb.171.7.3840-3845.1989.
The xyl operator of Bacillus subtilis W23 was identified by deletion analysis of the xyl regulatory region as a 25-base-pair (bp) sequence located 10 bp downstream from the xyl promoter. The outer 10 bp of the xyl operator exhibit perfect palindromic symmetry, while 5 central bp are nonpalindromic. It was demonstrated that the penultimate base pair near the end of this sequence is important for repressor binding. The location of the xylR gene encoding the repressor was determined by its ability to mediate xylose-dependent repression of a xyl-cat fusion on a multicopy plasmid. The nucleotide sequence of 1,355 bp from this DNA was analyzed and contains an open reading frame with a coding capacity for 384 amino acids leading to a protein with a calculated molecular weight of 42,270. A mutant with a deletion in this reading frame showed no repression of the xyl-cat fusion. The coding sequence is preceded by a suitable ribosome-binding sequence and uses GTG as a start codon and TAA as a stop codon. The relationship of these results to corresponding data obtained from B. subtilis 168 is discussed.
通过对木糖调节区域的缺失分析，确定枯草芽孢杆菌W23的木糖操纵子是位于木糖启动子下游10 bp处的一段25个碱基对（bp）的序列。木糖操纵子外侧的10 bp呈现出完美的回文对称性，而中间的5 bp是非回文的。已证明该序列末端附近的倒数第二个碱基对对于阻遏物结合很重要。编码阻遏物的xylR基因的位置是通过其介导多拷贝质粒上木糖 - 猫融合体的木糖依赖性阻遏的能力来确定的。对该DNA的1355 bp核苷酸序列进行了分析，其中包含一个开放阅读框，编码能力为384个氨基酸，产生一种计算分子量为42,270的蛋白质。该阅读框中有缺失的突变体对木糖 - 猫融合体没有阻遏作用。编码序列之前有合适的核糖体结合序列，使用GTG作为起始密码子，TAA作为终止密码子。讨论了这些结果与从枯草芽孢杆菌168获得的相应数据的关系。
