title: Determination of subunit composition of Clostridium cellulovorans cellulosomes that degrade plant cell walls.
abstract: Clostridium cellulovorans produces a cellulase enzyme complex (cellulosome). In this study, we isolated two plant cell wall-degrading cellulosomal fractions from culture supernatant of C. cellulovorans and determined their subunit compositions and enzymatic activities. One of the cellulosomal fractions showed fourfold-higher plant cell wall-degrading activity than the other. Both cellulosomal fractions contained the same nine subunits (the scaffolding protein CbpA, endoglucanases EngE and EngK, cellobiohydrolase ExgS, xylanase XynA, mannanase ManA, and three unknown proteins), although the relative amounts of the subunits differed. Since only cellobiose was released from plant cell walls by the cellulosomal fractions, cellobiohydrolases were considered to be key enzymes for plant cell wall degradation.
authors.affiliation: Section of Molecular, University of California, Davis, California 95616, USA.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Murashima
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kosugi
authors.forename: Roy H
authors.initials: RH
authors.lastname: Doi
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D002473:Cell Wall / Q000378:metabolism*; D002480:Cellulase / Q000737:chemistry* / Q000378:metabolism; D043366:Cellulose 1,4-beta-Cellobiosidase; D003013:Clostridium / Q000201:enzymology* / Q000254:growth & development; D003470:Culture Media; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism; D018514:Plant Structures / Q000378:metabolism*
chemical_list: D003470:Culture Media; D009097:Multienzyme Complexes; D002480:Cellulase; D043366:Cellulose 1,4-beta-Cellobiosidase