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- ******************************
- * Guanylate kinase signature *
- ******************************
-
- Guanylate kinase (EC 2.7.4.8) (GK) [1] catalyzes the ATP-dependent
- phosphorylation of GMP into GDP. It is essential for recycling GMP and
- indirectly, cGMP. In prokaryotes (such as Escherichia coli), lower eukaryotes
- (such as yeast) and in vertebrates, GK is a highly conserved monomeric
- protein of about 200 amino acids. GK has been shown [2,3,4] to be structurally
- similar to the following proteins:
-
- - Protein A57R (or SalG2R) from various strains of Vaccinia virus. This
- protein is highly similar to GK, but contains a frameshift mutation in the
- N-terminal section and could therefore be inactive in that virus.
-
- The following proteins are characterized by the presence in their sequence of
- a SH3 domain as well as a C-terminal GK-like domain:
-
- - Drosophila lethal(1)discs large-1 tumor suppressor protein (gene dlg1).
- This protein is associated with septate junctions in developing flies and
- defects in the dlg1 gene cause neoplastic overgrowth of the imaginal disks.
- Dlg1 is a protein of 960 amino acids.
- - Rat postsynaptic density protein 95 (PSD-95). PSD-95 is a protein of 724
- amino acids which is enriched in the postsynaptic density fraction.
- - Human 55 Kd erythrocyte membrane protein (p55). p55 is a palmitoylated,
- membrane-associated protein of unknown function. p55 is a protein of 460
- amino acids.
-
- There is an ATP-binding site (P-loop) in the N-terminal section of GK. This
- region is not conserved in the GK-like domain of the above proteins which are
- therefore unlikely to be kinases. However these proteins retain the residues
- known, in GK, to be involved in the binding of GMP. As a signature pattern we
- selected a highly conserved region that contains two arginine and a tyrosine
- which are involved in GMP-binding.
-
- -Consensus pattern: T-T-R-x(2)-R-x(2)-E-x(2)-G-x(2)-Y-x-[FY]-[LIVM]
- -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] Stehle T., Schulz G.E.
- J. Mol. Biol. 224:1127-1141(1992).
- [ 2] Bryant P.J., Woods D.F.
- Cell 68:621-622(1992).
- [ 3] Goebl M.G.
- Trends Biochem. Sci. 17:99-99(1992).
- [ 4] Zschocke P.D., Schiltz E., Schulz G.E.
- Eur. J. Biochem. 213:263-269(1993).
-