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- **************************************************
- * LacY family proton/sugar symporters signatures *
- **************************************************
-
- In bacteria there are a number of families of transport proteins that mediate
- the intake of a variety of sugars with the concomitant uptake of hydrogen
- ions (proton symporters) [1]. One of these families is composed [2] of the
- following proteins:
-
- - Escherichia coli and Klebsiella pneumoniae lactose permease (gene lacY)
- which are responsible for the transport of beta-galactosides into the cell.
- - Escherichia coli plasmid pRsd2 raffinose permease (gene rafB).
- - Escherichia coli sucrose permease (gene cscB).
-
- These integral membrane proteins are predicted to comprise twelve membrane
- spanning domains. As signature patterns we selected two conserved regions
- that both correspond to cytoplasmic loops: between the second and third
- transmembrane regions for the first pattern and between the eight and ninth
- for the second pattern.
-
- -Consensus pattern: G-[LIVM](2)-x-D-[RK]-L-G-L-[RK](2)-x-[LIVM](2)-W
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: P-x-[LIVMF](2)-N-R-[LIVM]-G-x-K-N-[STA]-[LIVM](3)
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Last update: October 1993 / First entry.
-
- [ 1] Marger M.D., Saier M.H. Jr.
- Trends Biochem. Sci. 18:13-20(1993).
- [ 2] Bockmann J., Heuel H., Lengeler J.W.
- Mol. Gen. Genet. 235:22-32(1992).
-