Maloy S R, Nunn W D
J Bacteriol. 1982 Jan;149(1):173-80. doi: 10.1128/jb.149.1.173-180.1982.
The expression of the glyoxylate shunt enzymes is required for growth of Escherichia coli on acetate or fatty acids as a sole carbon source. The genes for the two unique enzymes of the glyoxylate shunt, aceA and aceB, are located at 90 min on the E. coli K-12 genetic map. Polar mutations in the aceB gene eliminate aceA gene function, suggesting that these genes constitute an operon and the direction of transcription is from aceB to aceA. Mu d (Ap lac) fusions with the aceA gene have been constructed to study the regulation of the ace operon. Expression of the ace operon is under the transcriptional control of two genes: the iclR gene, which maps near the ace operon, and the fadR gene, which maps at 25 min, and is also involved in the regulation of the fatty acid degradation (fad) regulon. Merodiploid studies demonstrated that both the iclR and fadR genes regulate the glyoxylate shunt in a trans-dominant manner.
乙醛酸循环支路酶的表达是大肠杆菌在以乙酸盐或脂肪酸作为唯一碳源时生长所必需的。乙醛酸循环支路的两种独特酶的基因，即aceA和aceB，位于大肠杆菌K-12遗传图谱的90分钟处。aceB基因中的极性突变消除了aceA基因的功能，这表明这些基因构成一个操纵子，转录方向是从aceB到aceA。已构建与aceA基因的Mu d(Ap lac)融合体来研究ace操纵子的调控。ace操纵子的表达受两个基因的转录控制：位于ace操纵子附近的iclR基因，以及位于25分钟处的fadR基因，fadR基因也参与脂肪酸降解（fad）调节子的调控。部分二倍体研究表明，iclR和fadR基因均以反式显性方式调节乙醛酸循环支路。
