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* Binding-protein-dependent transport systems inner membrane component *
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Bacterial binding protein-dependent transport systems [1,2] are multicomponent
systems typically composed of a periplasmic substrate-binding protein,  one or
two reciprocally  homologous integral inner-membrane proteins  and  one or two
peripheral  membrane  ATP-binding  proteins  that  couple energy to the active
transport system.

The integral  inner-membrane  proteins  translocate  the  substrate across the
membrane. It  has  been  shown  [3]  that  most  of  these  proteins contain a
conserved region  located  about  80  to  100  residues from their  C-terminal
extremity. This  region  seems [4] to be located in a cytoplasmic loop between
two transmembrane  domains.  Proteins  belonging  to  this  family  are listed
below (references are only provided for recently sequenced proteins).

      Name(s)       Transport system
      -----------   --------------------------------------
      amiC  amiD    Oligopeptides
      artM  artQ    Arginine
      cysT  cysW    Sulfate / thiosulfate
      dciAB dciAC   Dipeptides
      hisM  hisQ    Histidine
      malF  malG    Maltose
      msmF  msmG    Melibiose / raffinose / isomaltotriose
      modB          Molybdenum
      nifC          Molybdenum (?)
      nikB  nikC    Nickel
      oppB  oppC    Oligopeptides
      phnM          Alkylphosphonate (?)
      potB  potC    Spermidine/putrescine
      potH  potI    Putrescine                   [5]
      proW          Glycine betaine / L-proline
      pstA  pstC    Phosphate
      sapB  sapC    Peptides                     [6]
      ugpA  ugpE    sn-glycerol-3-phosphate

      mbpY          Unknown, from chloroplast of Marchantia polymorpha
      yehW  yehY    Unknown, from Escherichia coli

We built  a  signature  pattern  from  the best conserved positions within the
conserved region.

-Consensus pattern: [LIVMFY]-x(8)-[EQR]-[STAV]-[STAG]-x(3)-G-[LIVMFYSTAC]-
                    x(5)-[LIVMFYSTA]-x(4)-[LIVMFY]-[PKR]
-Sequences known to belong to this class detected by the pattern: the majority
 of these proteins with the  exception of amiC, amiD, artM, dciAC, lacG, nikB,
 nikC, phnM, sapB, and sapC.
-Other sequence(s) detected in SWISS-PROT: 26.
-Last update: June 1994 / Pattern and text revised.

[ 1] Ames G.F.-L.
     Annu. Rev. Biochem. 55:397-425(1986).
[ 2] Higgins C.F., Hyde S.C., Mimmack M.M., Gileadi U., Gill D.R.,
     Gallagher M.P.
     J. Bioenerg. Biomembr. 22:571-592(1990).
[ 3] Dassa E., Hofnung M.
     EMBO J. 4:2287-2293(1985).
[ 4] Pearce S.R., Mimmack M.L., Gallagher M.P., Gileadi U., Hyde S.C.,
     Higgins C.F.
     Mol. Microbiol. 6:57-57(1992).
[ 5] Pistocchi R., Kashiwagi K., Miyamoto S., Nukui E., Sadakata Y.,
     Kobayashi H., Igarashi K.
     J. Biol. Chem. 268:146-152(1993).
[ 6] Parra-Lopez C., Baer M.T., Groisman E.A.
     EMBO J. 12:4053-4062(1993).