Two novel families of bacterial membrane proteins concerned with nodulation, cell division and transport.
Homology has been established for members of two families of functionally related bacterial membrane proteins. The first family (the resistance/nodulation/cell division (RND) family) includes (i) two metal-resistance efflux pumps in Alcaligenes eutrophus (CzcA and CnrA), (ii) three proteins which function together in nodulation of alfalfa roots by Rhizobium meliloti (NoIGHI), and (iii) a cell division protein in Escherichia coli (EnvD). The second family (the putative membrane fusion protein (MFP) family) includes a nodulation protein (NoIF), a cell division protein (EnvC), and a multidrug resistance transport protein (EmrA). We propose that an MFP functions co-operatively with an RND protein to transport large or hydrophobic molecules across the two membranes of the Gram-negative bacterial cell envelope.
Department of Biology, University of California at San Diego, La Jolla 92093-0116.
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D000421:Alcaligenes / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport / Q000235:genetics; D002352:Carrier Proteins / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000235:genetics; D016384:Consensus Sequence; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D000455:Medicago sativa / Q000382:microbiology; D008565:Membrane Proteins / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D008670:Metals / Q000494:pharmacology; D008969:Molecular Sequence Data; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D005810:Multigene Family; D009876:Operon; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D016962:Sinorhizobium meliloti / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D008670:Metals; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C083496:AcrB protein, E coli; C489681:EmrA protein, E coli; C071960:acrF protein, E coli; C077168:emrA protein, Bacteria