title: A transporter of Escherichia coli specific for L- and D-methionine is the prototype for a new family within the ABC superfamily.
abstract: An ABC-type transporter in Escherichia coli that transports both L- and D-methionine, but not other natural amino acids, was identified. This system is the first functionally characterized member of a novel family of bacterial permeases within the ABC superfamily. This family was designated the methionine uptake transporter (MUT) family (TC #3.A.1.23). The proteins that comprise the transporters of this family were analyzed phylogenetically, revealing the probable existence of several sequence-divergent primordial paralogues, no more than two of which have been transmitted to any currently sequenced organism. In addition, MetJ, the pleiotropic methionine repressor protein, was shown to negatively control expression of the operon encoding the ABC-type methionine uptake system. The identification of MetJ binding sites (in gram-negative bacteria) or S-boxes (in gram-positive bacteria) in the promoter regions of several MUT transporter-encoding operons suggests that many MUT family members transport organic sulfur compounds.
authors.affiliation: Division of Biological Sciences, University of California at San Diego, CA 92093-0116, La Jolla, USA.
authors.forename: Zhongge
authors.initials: Z
authors.lastname: Zhang
authors.forename: Jérôme N
authors.initials: JN
authors.lastname: Feige
authors.forename: Abraham B
authors.initials: AB
authors.lastname: Chang
authors.forename: Iain J
authors.initials: IJ
authors.lastname: Anderson
authors.forename: Vadim M
authors.initials: VM
authors.lastname: Brodianski
authors.forename: Alexei G
authors.initials: AG
authors.lastname: Vitreschak
authors.forename: Mikhail S
authors.initials: MS
authors.lastname: Gelfand
authors.forename: Milton H
authors.initials: MH
authors.lastname: Saier
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000502:physiology; D005075:Biological Evolution; D001693:Biological Transport, Active; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D008715:Methionine / Q000378:metabolism* / Q000494:pharmacology; D009239:N-Formylmethionine / Q000494:pharmacology*; D009876:Operon; D010802:Phylogeny; D012097:Repressor Proteins / Q000502:physiology
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; C060486:methionine repressor protein, Bacteria; C489220:methionine repressor protein, E coli; D009239:N-Formylmethionine; D008715:Methionine