title: A large gene cluster for the Clostridium cellulovorans cellulosome.
abstract: A large gene cluster for the Clostridium cellulovorans cellulosome has been cloned and sequenced upstream and downstream of the cbpA and exgS genes (C.-C. Liu and R. H. Doi, Gene 211:39-47, 1998). Gene walking revealed that the engL gene cluster (Y. Tamaru and R. H. Doi, J. Bacteriol. 182:244-247, 2000) was located downstream of the cbpA-exgS genes. Further DNA sequencing revealed that this cluster contains the genes for the scaffolding protein CbpA, the exoglucanase ExgS, several endoglucanases of family 9, the mannanase ManA, and the hydrophobic protein HbpA containing a surface layer homology domain and a hydrophobic (or cohesin) domain. The sequence of the clustered genes is cbpA-exgS-engH-engK-hbpA-engL-man A-engM-engN and is about 22 kb in length. The engN gene did not have a complete catalytic domain, indicating that engN is a truncated gene. This large gene cluster is flanked at the 5' end by a putative noncellulosomal operon consisting of nifV-orf1-sigX-regA and at the 3' end by noncellulosomal genes with homology to transposase (trp) and malate permease (mle). Since gene clusters for the cellulosome are also found in C. cellulolyticum and C. josui, they seem to be typical of mesophilic clostridia, indicating that the large gene clusters may arise from a common ancestor with some evolutionary modifications.
authors.affiliation: Section of Molecular and Cellular Biology, University of California, Davis, California 95616, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Tamaru
authors.forename: S
authors.initials: S
authors.lastname: Karita
authors.forename: A
authors.initials: A
authors.lastname: Ibrahim
authors.forename: H
authors.initials: H
authors.lastname: Chan
authors.forename: R H
authors.initials: RH
authors.lastname: Doi
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics; D002482:Cellulose / Q000378:metabolism*; D043366:Cellulose 1,4-beta-Cellobiosidase; D003013:Clostridium / Q000235:genetics* / Q000378:metabolism; D005959:Glucosidases / Q000737:chemistry / Q000235:genetics*; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics; D008361:Mannosidases / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D015183:Restriction Mapping; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D044902:beta-Mannosidase
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C074074:cellulose binding protein A, Clostridium cellulovorans; D002482:Cellulose; D005959:Glucosidases; D006026:Glycoside Hydrolases; D008361:Mannosidases; D044902:beta-Mannosidase; D043366:Cellulose 1,4-beta-Cellobiosidase; C112612:ExgS protein, Clostridium cellulovorans