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- *************************************************************
- * Clostridium cellulosome enzymes repeated domain signature *
- *************************************************************
-
- Gram-positive, thermophilic anaerobes such as Clostridium thermocellum or
- Clostridium cellulolyticum secretes a highly active and thermostable cellulase
- complex (cellulosome) responsible for the degradation of crystalline cellulose
- [1,2]. The cellulosome contains at least 30 polypeptides, the majority of the
- enzymes are endoglucanases (EC 3.2.1.4), but there are also some xylanases
- (EC 3.2.1.8), beta-glucosidases (EC 3.2.1.21) and endo-beta-1,3-1,4-glucanases
- (EC 3.2.1.73).
-
- Complete sequence data for many of these enzymes has been obtained. A majority
- of these proteins contain a highly conserved region of about 65 to 70 residues
- which is generally (but not always) located in the C-terminus. This region
- contains a duplicated segment of 24 amino acids. The function of this
- duplicated segment is not yet known, although it has been suggested that it
- could be involved in substrate-binding or in calcium-binding [3].
-
- Currently this domain has been found in:
-
- - Endoglucanases A (celA), B (celB), D (celD), E (celE), F (celF), G (celG),
- H (celH), and X (celX) from Clostridium thermocellum.
- - Endoglucanase A (celCCA) and D (celCCD) from Clostridium cellulolyticum.
- - Endoglucanase B (engB) from Clostridium cellulovorans.
- - Xylanase Z (xynZ) from Clostridium thermocellum.
- - Endo-beta-1,3-1,4 glucanase (licB) from Clostridium thermocellum.
-
- The pattern we developed spans the first 21 positions of the 24 amino acids
- segment.
-
- -Consensus pattern: D-[LIVMFY]-[DN]-x-[DNS]-x(2)-[LIVM]-[DN]-[SA]-x-D-x(3)-
- [LIVMF]-x-[RKS]-x-[LIVM](2)
- -Sequences known to belong to this class detected by the pattern: ALL. In all
- cases that pattern is detected twice.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Expert(s) to contact by email: Beguin P.
- phycel@pasteur.bitnet
-
- -Last update: June 1994 / Pattern and text revised.
-
- [ 1] Beguin P.
- Annu. Rev. Microbiol. 44:219-248(1990).
- [ 2] Beguin P., Millet J., Aubert J.-P.
- FEMS Microbiol. Lett. 100:523-528(1992).
- [ 3] Chauvaux S., Beguin P., Aubert J.-P., Bhat K.M., Gow L.A., Wood T.M.,
- Bairoch A.
- Biochem. J. 265:261-265(1990).
-