Coleman J
Department of Biochemistry and Molecular Biology, Louisiana State University-Medical Center, New Orleans 70112.
Mol Gen Genet. 1992 Mar;232(2):295-303. doi: 10.1007/BF00280009.
An Escherichia coli strain deficient in 1-acyl-sn-glycerol-3-phosphate acyltransferase activity has previously been isolated, and the gene (plsC) has been shown to map near min 65 on the chromosome. I precisely mapped the location of plsC on the chromosome, and determined its DNA sequence. plsC is located between parC and sufI, and is separated from sufI by 74 bp. Upstream of plsC is parC, separated by 233 bp, which includes an active promoter. parC, plsC, and sufI are all transcribed in the counterclockwise direction on the chromosome, possibly in an operon with multiple promoters. The amino-terminal sequence of the partially purified protein, combined with the DNA sequence, reveal 1-acyl-sn-glycerol-3-phosphate acyltransferase to be a 27.5 kDa highly basic protein. The plsC gene product, 1-acyl-sn-glycerol-3-phosphate acyltransferase, is localized to the cytoplasmic membrane of the cell. The amino-terminal sequence of the purified protein reveals the first amino acid to be a blocked methionine residue, most probably a formyl-methionine. The amino acid sequence of 1-acyl-sn-glycerol-3-phosphate acyltransferase has a short region of homology to two other E. coli acyltransferases that utilize acyl-acyl carrier protein as the acyl donor, sn-glycerol-3-phosphate acyltransferase and UDP-N-acetyl-glucosamine acyltransferase (involved in lipid A biosynthesis).
先前已分离出一株缺乏1-酰基-sn-甘油-3-磷酸酰基转移酶活性的大肠杆菌菌株，并且已证明该基因（plsC）位于染色体上65分钟附近。我精确地绘制了plsC在染色体上的位置，并确定了其DNA序列。plsC位于parC和sufI之间，与sufI相隔74个碱基对。plsC的上游是parC，相隔233个碱基对，其中包括一个活性启动子。parC、plsC和sufI都在染色体上沿逆时针方向转录，可能在一个具有多个启动子的操纵子中。部分纯化蛋白质的氨基末端序列与DNA序列相结合，表明1-酰基-sn-甘油-3-磷酸酰基转移酶是一种27.5 kDa的高碱性蛋白质。plsC基因产物1-酰基-sn-甘油-3-磷酸酰基转移酶定位于细胞的细胞质膜。纯化蛋白质的氨基末端序列显示第一个氨基酸是一个被封闭的甲硫氨酸残基，很可能是甲酰甲硫氨酸。1-酰基-sn-甘油-3-磷酸酰基转移酶的氨基酸序列与另外两种利用酰基-酰基载体蛋白作为酰基供体的大肠杆菌酰基转移酶，即sn-甘油-磷酸酰基转移酶和UDP-N-乙酰葡糖胺酰基转移酶（参与脂多糖A生物合成）有一个短的同源区域。
