Expression and regulation of a silent operon, hyf, coding for hydrogenase 4 isoenzyme in Escherichia coli
Expression and regulation of a silent operon, hyf, coding for hydrogenase 4 isoenzyme in Escherichia coli
复制标题
DOI：
10.1128/jb.186.2.580-587.2004
复制
发表时间：
2004-01-01
影响因子：
3.2
通讯作者：
Shanmugam, KT
中科院分区：
文献类型：
--
作者：
Self, WT;Hasona, A;Shanmugam, KT
hyf-lacZ融合研究的基础上，大肠杆菌的hyf操纵子，注意到编码第四氢化酶同工酶（HYD 4），在野生型菌株中不表达在一个显着的水平。然而，突变体FhlA蛋白（hyc编码的氢化酶3同工酶的组成型激活剂）激活hyf-lacZ。HYfR，一种由hyf操纵子末端的hyfR基因编码的FhlA同源物，也激活hyf-lacZ的转录，但只有当hyfR从异源启动子表达时才激活。HYD 4同工酶在H-2产生中不能代替HYD 3。hyf-lacZ的最佳表达需要环AMP受体蛋白-环AMP复合物的存在和厌氧条件下，HyfR是激活剂。
On the basis of hyf-lacZ fusion studies, the hyf operon of Escherichia coli, noted for encoding the fourth hydrogenase isoenzyme (HYD4), is not expressed at a significant level in a wild-type strain. However, mutant FhlA proteins (constitutive activators of the hyc-encoded hydrogenase 3 isoenzyme) activated hyf-lacZ. HYfR, an FhlA homolog encoded by the hyfR gene present at the end of the hyf operon, also activated transcription of hyf-lacZ but did so only when hyfR was expressed from a heterologous promoter. The HYD4 isoenzyme did not substitute for HYD3 in H-2 production. Optimum expression of hyf-lacZ required the presence of cyclic AMP receptor protein-cyclic AMP complex and anaerobic conditions when HyfR was the activator.