Wang Y L, Beach M J, Rodwell V W
Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907.
J Bacteriol. 1989 Oct;171(10):5567-71. doi: 10.1128/jb.171.10.5567-5571.1989.
We have cloned and sequenced a 505-base-pair (bp) segment of DNA situated upstream of mvaA, the structural gene for (S)-3-hydroxy-3-methylglutaryl coenzyme A reductase (EC 1.1.1.88) of Pseudomonas mevalonii. The DNA segment that we characterized includes the promoter region for the mva operon. Nuclease S1 mapping and primer extension analysis showed that mvaA is the promoter-proximal gene of the mva operon. Transcription initiates at -56 bp relative to the first A (+1) of the translation start site. Transcription in vivo was induced by mevalonate. Structural features of the mva promoter region include an 80-bp A + T-rich region, and -12, -24 consensus sequences that resemble sequences of sigma 54 promoters in enteric organisms. The relative amplitudes of catalytic activity, enzyme protein, and mvaA mRNA are consistent with a model of regulation of this operon at the transcriptional level.
我们已经克隆并测序了位于甲羟戊酸假单胞菌（Pseudomonas mevalonii）的（S）-3-羟基-3-甲基戊二酰辅酶A还原酶（EC 1.1.1.88）的结构基因mvaA上游的一段505个碱基对（bp）的DNA片段。我们鉴定的这段DNA片段包含mva操纵子的启动子区域。核酸酶S1作图和引物延伸分析表明，mvaA是mva操纵子中最靠近启动子的基因。转录起始于相对于翻译起始位点的第一个A（+1）的-56 bp处。体内转录由甲羟戊酸诱导。mva启动子区域的结构特征包括一个80 bp富含A+T的区域，以及类似于肠道生物中σ54启动子序列的-12、-24共有序列。催化活性、酶蛋白和mvaA mRNA的相对幅度与该操纵子在转录水平上的调控模型一致。
