title: Structure of a family 3a carbohydrate-binding module from the cellulosomal scaffoldin CipA of Clostridium thermocellum with flanking linkers: implications for cellulosome structure.
abstract: The cellulosome of the cellulolytic bacterium Clostridium thermocellum has a structural multi-modular protein called CipA (cellulosome-integrating protein A) that includes nine enzyme-binding cohesin modules and a family 3 cellulose-binding module (CBM3a). In the CipA protein, the CBM3a module is located between the second and third cohesin modules and is connected to them via proline/threonine-rich linkers. The structure of CBM3a with portions of the C- and N-terminal flanking linker regions, CBM3a-L, has been determined to a resolution of 1.98 Å. The structure is a β-sandwich with a structural Ca(2+) ion. The structure is consistent with the previously determined CipA CBM structure; however, the structured linker regions provide a deeper insight into the overall cellulosome structure and assembly.
authors.affiliation: Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel.
authors.forename: Oren
authors.initials: O
authors.lastname: Yaniv
authors.forename: Ely
authors.initials: E
authors.lastname: Morag
authors.forename: Ilya
authors.initials: I
authors.lastname: Borovok
authors.forename: Edward A
authors.initials: EA
authors.lastname: Bayer
authors.forename: Raphael
authors.initials: R
authors.lastname: Lamed
authors.forename: Felix
authors.initials: F
authors.lastname: Frolow
authors.forename: Linda J W
authors.initials: LJ
authors.lastname: Shimon
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D044602:Cellulases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D044603:Cellulosomes / Q000378:metabolism*; D048013:Acetivibrio thermocellus / Q000235:genetics / Q000378:metabolism*; D003460:Crystallization; D018360:Crystallography, X-Ray; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation
chemical_list: D001426:Bacterial Proteins; C080369:CipA protein, Clostridium; D008565:Membrane Proteins; D044602:Cellulases
keywords: CipA; Clostridium thermocellum; cellulosome; family 3 cellulose-binding module