Allison S L, Phillips A T
Department of Molecular and Cell Biology, Althouse Laboratory, Pennsylvania State University, University Park 16802.
J Bacteriol. 1990 Sep;172(9):5470-6. doi: 10.1128/jb.172.9.5470-5476.1990.
The hutC gene of Pseudomonas putida encodes a repressor which, in combination with the inducer urocanate, regulates expression of the five structural genes necessary for conversion of histidine to glutamate, ammonia, and formate. The nucleotide sequence of the hutC region was determined and found to contain two open reading frames which overlapped by one nucleotide. The first open reading frame (ORF1) appeared to encode a 27,648-dalton protein of 248 amino acids whose sequence strongly resembled that of the hut repressor of Klebsiella aerogenes (A. Schwacha and R. A. Bender, J. Bacteriol. 172:5477-5481, 1990) and contained a helix-turn-helix motif that could be involved in operator binding. The gene was preceded by a sequence which was nearly identical to that of the operator site located upstream of hutU which controls transcription of the hutUHIG genes. The operator near hutC would presumably allow the hut repressor to regulate its own synthesis as well as the expression of the divergent hutF gene. A second open reading frame (ORF2) would encode a 21,155-dalton protein, but because this region could be deleted with only a slight effect on repressor activity, it is not likely to be involved in repressor function or structure.
恶臭假单胞菌的hutC基因编码一种阻遏物，该阻遏物与诱导剂尿刊酸结合后，可调控将组氨酸转化为谷氨酸、氨和甲酸所需的5个结构基因的表达。测定了hutC区域的核苷酸序列，发现其包含两个开放阅读框，它们有一个核苷酸的重叠。第一个开放阅读框（ORF1）似乎编码一个由248个氨基酸组成、分子量为27,648道尔顿的蛋白质，其序列与产气克雷伯菌的hut阻遏物的序列非常相似（A. Schwacha和R. A. Bender，《细菌学杂志》172:5477 - 5481，1990年），并且含有一个可能参与操纵子结合的螺旋-转角-螺旋基序。该基因之前的一段序列与位于hutU上游、控制hutUHIG基因转录的操纵子位点的序列几乎相同。hutC附近的操纵子可能允许hut阻遏物调控其自身的合成以及反向排列的hutF基因的表达。第二个开放阅读框（ORF2）将编码一个分子量为21,155道尔顿的蛋白质，但由于该区域的缺失对阻遏物活性只有轻微影响，所以它不太可能参与阻遏物的功能或结构。
