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- ****************************************************
- * Sodium:dicarboxylate symporter family signatures *
- ****************************************************
-
- It has been shown [1] that integral membrane proteins that mediate the intake
- of a wide variety of molecules with the concomitant uptake of sodium ions
- (sodium symporters) can be grouped, on the basis of sequence and functional
- similarities into a number of distinct families. One of these families [2] is
- known as the sodium:dicarboxylate symporter family (SDF) and currently
- consists of the following proteins:
-
- - Escherichia coli proton-glutamate symport protein (glutamate-aspartate
- carrier) (gene gltP). GltP is a sodium-independent carrier for glutamate
- and aspartate.
- - Bacillus caldotenax and stearothermophilus proton/sodium-glutamate symport
- protein (gene gltT). GltT is a sodium-dependent carrier for glutamate and
- aspartate.
- - Rhizobium C4-dicarboxlate carrier (gene dctA), which is responsible for the
- transport of dicarboxylates such as succinate, fumarate, and malate. This
- transport system plays an important role in the energy supply of Rhizobium-
- legume symbionts.
- - Mammalian brain sodium-dependent L-glutamate and aspartate high-affinity
- transporters [3,4]. These proteins are essential for terminating the
- postsynaptic action of glutamate by rapidly removing released glutamate
- from the synaptic cleft.
-
- These transporters are proteins of from 420 to 573 amino acids which are
- highly hydrophobic and which probably contain about 10 transmembrane regions.
- As signature patterns, we selected two conserved regions. The first pattern is
- located in the N-terminal section and seems to include a hydrophilic region
- between two transmembrane regions. The second pattern is located in the C-
- terminal section.
-
- -Consensus pattern: D-x(4)-G-[KR]-[LIVM]-[GA]-x-[KR]-[STA]-[LIVMA](2)-[YF](2)
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: P-x-G-x-[STA]-x-N-[LIVM]-D-G-[ST]-x-[LIVM]-Y-x(2)-[LIVM]-
- A-A-[LIVM]-F-I-A-Q
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Expert(s) to contact by email: Hofmann K.O.
- khofmann@isrec-sun1.unil.ch
- Reizer J.
- jreizer@ucsd.edu
-
- -Last update: June 1994 / Text revised.
-
- [ 1] Reizer J., Reizer A., Saier M.H. Jr.
- Submitted(1993).
- [ 2] Storck T., Schulte S., Hofmann K.O., Stoffel W.
- Proc. Natl. Acad. Sci. U.S.A. 89:10955-10959(1992).
- [ 3] Kanner B.I.
- FEBS Lett. 325:95-99(1993).
- [ 4] Kanai Y., Smith C.P., Hediger M.A.
- FASEB J. 7:1450-1459(1993).
-