Blazey D L, Burns R O
J Bacteriol. 1984 Sep;159(3):951-7. doi: 10.1128/jb.159.3.951-957.1984.
The Salmonella typhimurium LT2 ilvYC genes were studied by fusion of each gene to the Escherichia coli K-12 galK gene. The expression of ilvY and ilvC could then be determined by measurement of the galK-encoded galactokinase enzyme. The promoter for ilvC, pC, was located by this technique to a 0.42-kilobase BglII-EcoRI fragment of the S. typhimurium ilvGEDAYC gene cluster. This sequence was completely sufficient for alpha-acetohydroxyacid-inducible galK expression. The ilvY gene was located within a 1.0-kilobase XhoI-SalI fragment. ilvY gene expression was constitutive with respect to ilv-specific control signals. The ilvY gene was transcribed in the same direction as the other two transcriptional units in the ilvGEDAYC gene cluster, ilvGEDA and ilvC. Transcription of the ilvC gene was completely dependent upon the activity of its own promoter, pC, and independent from transcription of the ilvY gene. The role of the intervening region between ilvY and ilvC in regulation of ilvC expression was explored.
通过将鼠伤寒沙门氏菌LT2的ilvYC基因与大肠杆菌K-12的galK基因融合，对这些基因进行了研究。然后可以通过测量galK编码的半乳糖激酶来确定ilvY和ilvC的表达。通过该技术将ilvC的启动子pC定位到鼠伤寒沙门氏菌ilvGEDAYC基因簇的一个0.42千碱基的BglII-EcoRI片段上。该序列对于α-乙酰羟酸诱导的galK表达是完全足够的。ilvY基因位于一个1.0千碱基的XhoI-SalI片段内。就ilv特异性控制信号而言，ilvY基因的表达是组成型的。ilvY基因与ilvGEDAYC基因簇中的其他两个转录单位ilvGEDA和ilvC转录方向相同。ilvC基因的转录完全依赖于其自身启动子pC的活性，并且独立于ilvY基因的转录。探索了ilvY和ilvC之间的间隔区域在ilvC表达调控中的作用。
