{PDOC00416} {PS00448; CLOS_CELLULOSOME_RPT} {BEGIN} ************************************************************* * 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. - Endoglucanases A (celCCA), C (celCCC), D (celCCD), F (celCCF) and G (celCCG) from Clostridium cellulolyticum. - Endoglucanase B (engB) from Clostridium cellulovorans. - Xylanases Y (XynY) and Z (xynZ) from Clostridium thermocellum. - Endo-beta-1,3-1,4 glucanase (licB) from Clostridium thermocellum. - Cellulose integrating protein (cipA) from Clostridium thermocellum. CipA acts as a scaffolding protein in the cellulosome. It promotes binding of cellulose to the catalytic domains of the cellulolytic enzymes [4]. The pattern we developed spans the first 20 positions of the 24 amino acids segment. -Consensus pattern: D-[LIVMFY]-[DNV]-x-[DNS]-x(2)-[LIVM]-[DN]-[SALM]-x-D-x(3)- [LIVMF]-x-[RKS]-x-[LIVMF] -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.; beguin@pasteur.fr -Last update: November 1997 / Text revised. [ 1] Beguin P. "Molecular biology of cellulose degradation." Annu. Rev. Microbiol. 44:219-248(1990). PubMed=2252383; DOI=10.1146/annurev.mi.44.100190.001251 [ 2] Beguin P., Millet J., Aubert J.-P. "Cellulose degradation by Clostridium thermocellum: from manure to molecular biology." FEMS Microbiol. Lett. 79:523-528(1992). PubMed=1478480 [ 3] Chauvaux S., Beguin P., Aubert J.-P., Bhat K.M., Gow L.A., Wood T.M., Bairoch A. "Calcium-binding affinity and calcium-enhanced activity of Clostridium thermocellum endoglucanase D." Biochem. J. 265:261-265(1990). PubMed=2302168 [ 4] Gerngross U.T., Romaniec M.P.M., Kobayashi T., Huskisson N.S., Demain A.L. "Sequencing of a Clostridium thermocellum gene (cipA) encoding the cellulosomal SL-protein reveals an unusual degree of internal homology." Mol. Microbiol. 8:325-334(1993). PubMed=8316083 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}