Allikmets R, Gerrard B, Court D, Dean M
Laboratory of Viral Carcinogenesis, National Cancer Institute, Frederick Cancer Research and Development Center, MD 21702.
Gene. 1993 Dec 22;136(1-2):231-6. doi: 10.1016/0378-1119(93)90470-n.
Using degenerate oligodeoxyribonucleotides from conserved regions of the gene family encoding ATP-binding domain of the active transporter, two new Escherichia coli genes were identified. The first of the genes, named mdl (multidrug resistance-like), is located at min 10.2 of the E. coli chromosome and encodes two ATP-binding motifs and two hydrophobic (transmembrane) domains. The ATP-binding domains of mdl show 35-38% amino acid (aa) identity with members of the eukaryotic P-glycoprotein/multidrug resistance family. To date, 25 members of the ATP-transporter/permease gene family have been characterized in E. coli. Comparison of the ATP-binding domains from this family indicates that mdl is part of a distinct subfamily of sequences that includes hlyB, msbA, and cvaB. Gene-disruption studies revealed that mdl is not essential for cell growth. The second open reading frame, named abc (ATP-binding cassette), is located at min 4.9 of the chromosome, encodes a single ATP-binding domain, and is most homologous to ftsE, a cell division control gene of E. coli. The abc gene product also shows aa sequence homology to several E. coli permeases.
利用编码主动转运蛋白ATP结合结构域的基因家族保守区域的简并寡脱氧核糖核苷酸，鉴定出两个新的大肠杆菌基因。第一个基因命名为mdl（多药耐药样），位于大肠杆菌染色体的10.2分钟处，编码两个ATP结合基序和两个疏水（跨膜）结构域。mdl的ATP结合结构域与真核P-糖蛋白/多药耐药家族成员的氨基酸（aa）同一性为35-38%。迄今为止，大肠杆菌中已鉴定出25个ATP转运蛋白/通透酶基因家族成员。对该家族ATP结合结构域的比较表明，mdl是一个独特序列亚家族的一部分，该亚家族包括hlyB、msbA和cvaB。基因破坏研究表明，mdl对细胞生长不是必需的。第二个开放阅读框命名为abc（ATP结合盒），位于染色体的4.9分钟处，编码一个单一的ATP结合结构域，与大肠杆菌的细胞分裂控制基因ftsE最同源。abc基因产物也与几种大肠杆菌通透酶显示出氨基酸序列同源性。
