A CLUSTER OF STRUCTURAL AND REGULATORY GENES FOR LIGHT-INDUCED CAROTENOGENESIS IN MYXOCOCCUS-XANTHUS
A CLUSTER OF STRUCTURAL AND REGULATORY GENES FOR LIGHT-INDUCED CAROTENOGENESIS IN MYXOCOCCUS-XANTHUS
复制标题
DOI：
10.1111/j.1432-1033.1995.238_1.x
复制
发表时间：
1995-10-01
期刊：
影响因子：
--
通讯作者：
RUIZVAZQUEZ, R
中科院分区：
文献类型：
--
作者：
BOTELLA, JA;MURILLO, FJ;RUIZVAZQUEZ, R
在细菌粘球菌xanthus中，几个类胡萝卜素合成基因位于carA-carB染色体位点，并被蓝光协同激活。野生型M.已经对包括整个carA-carB基因簇的xanthus进行了测序。根据序列分析，该簇包含11个不同的基因。基因间距离非常短或为零（意味着翻译偶联），进一步支持以前的证据表明，大多数（或所有）的基因簇形成一个单一的操纵子。在启动子区，发现一个潜在的σ因子结合位点-35，而-10区与其它细菌启动子类似位点的相似性很小。carA-carB操纵子中的五个（可能是六个）基因编码作用于类胡萝卜素合成途径早期或晚期步骤的酶。操纵子中的其他基因与先前已知的基因没有总体相似性。然而，在两个基因的预测产物中的肽段与MerR家族的转录调节因子的DNA结合结构域表现出很强的相似性。在受car基因光调节影响的突变株中，至少有一个预测的DNA结合结构域发生改变。
In the bacterium Myxococcus xanthus, several genes for carotenoid synthesis lie together at the carA-carB chromosomal locus and are co-ordinately activated by blue light. A 12-kb DNA stretch from wildtype M. xanthus has been sequenced that includes the entire carA-carB gene cluster. According to sequence analysis, the cluster contains 11 different genes. Intergenic distances are very short or nil (implying translational coupling), giving further support to previous evidence indicating that most (or all) of the genes in the cluster form a single operon. At the promoter region, a potential -35 site for the binding of sigma factors is found. However, the -10 region shows little similarity with analogous sites in other bacterial promoters. Five (possibly six) genes in the carA-carB operon code for enzymes acting on early or late steps of the pathway for carotenoid synthesis. Other genes in the operon show no overall similarity with previously known genes. However, peptide stretches in the predicted products of two genes exhibit strong similarity with the DNA binding domain of the MerR family of transcriptional regulators. At least one of the predicted DNA-binding domains is altered in a mutant strain affected in light-regulation of the car genes.