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- *************************************************
- * Eukaryotic-type carbonic anhydrases signature *
- *************************************************
-
- Carbonic anhydrases (EC 4.2.1.1) (CA) [1,2,3,4] are zinc metalloenzymes which
- catalyze the reversible hydration of carbon dioxide. Eight enzymatic and
- evolutionary related forms of carbonic anhydrase are currently known to exist
- in vertebrates: three cytosolic isozymes (CA-I, CA-II and CA-III); two
- membrane-bound forms (CA-IV and CA-VII); a mitochondrial form (CA-V); a
- secreted salivary form (CA-VI); and a yet uncharacterized isozyme [5].
-
- In the alga Chlamydomonas reinhardtii, two CA isozymes have been sequenced
- [6]. They are periplasmic glycoproteins evolutionary related to vertebrate
- CAs.
-
- CAs contain a single zinc atom bound to three conserved histidine residues.
- As a signature for CAs we used a pattern which includes one of these zinc-
- binding histidines.
-
- Protein D8 from Vaccinia and other poxviruses is related to CAs but has lost
- two of the zinc-binding histidines as well as many otherwise conserved
- residues. This is also true of the N-terminal extracellular domain of
- tyrosine-protein phosphatase RPTP gamma and zeta [7].
-
- -Consensus pattern: S-E-H-x-[LIVM]-x(4)-[FYH]-x(2)-E-[LIVM]-H-[LIVMFA](2)
- [The second H is a zinc ligand]
- -Sequences known to belong to this class detected by the pattern: ALL active
- CAs.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Note: prokaryotic and plant chloroplast CA's belong to another, evolutionary
- distinct family of proteins (see the relevant section).
-
- -Last update: June 1994 / Text revised.
-
- [ 1] Deutsch H.F.
- Int. J. Biochem. 19:101-113(1987).
- [ 2] Fernley R.T.
- Trends Biochem. Sci. 13:356-359(1988).
- [ 3] Tashian R.E.
- BioEssays 10:186-192(1989).
- [ 4] Edwards Y.
- Biochem. Soc. Trans. 18:171-175(1990).
- [ 5] Skaggs L.A., Bergenhem N.C.H., Venta P.J., Tashian R.E.
- Gene 126:291-292(1993).
- [ 6] Fujiwara S., Fukuzawa H., Tachiki A., Miyachi S.
- Proc. Natl. Acad. Sci. U.S.A. 87:9779-9783(1990).
- [ 7] Barnea G., Silvennoinen O., Shaanan B., Honegger A.M., Canoll P.D.,
- D'Eustachio P., Morse B., Levy J.B., Laforgia S., Huebner K.,
- Musacchio J., Sap J., Schlessinger J.
- Mol. Cell. Biol. 13:1497-1506(1993).
-