title: Cloning and organization of the abc and mdl genes of Escherichia coli: relationship to eukaryotic multidrug resistance.
abstract: 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.
authors.affiliation: Laboratory of Viral Carcinogenesis, National Cancer Institute, Frederick Cancer Research and Development Center, MD 21702.
authors.forename: R
authors.initials: R
authors.lastname: Allikmets
authors.forename: B
authors.initials: B
authors.lastname: Gerrard
authors.forename: D
authors.initials: D
authors.lastname: Court
authors.forename: M
authors.initials: M
authors.lastname: Dean
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D000255:Adenosine Triphosphate; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D004352:Drug Resistance, Microbial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C085503:mdlB protein, E coli; D000255:Adenosine Triphosphate