title: Recognition of xyloglucan by the crystalline cellulose-binding site of a family 3a carbohydrate-binding module.
abstract: Type A non-catalytic carbohydrate-binding modules (CBMs), exemplified by CtCBM3acipA, are widely believed to specifically target crystalline cellulose through entropic forces. Here we have tested the hypothesis that type A CBMs can also bind to xyloglucan (XG), a soluble β-1,4-glucan containing α-1,6-xylose side chains. CtCBM3acipA bound to xyloglucan in cell walls and arrayed on solid surfaces. Xyloglucan and cellulose were shown to bind to the same planar surface on CBM3acipA. A range of type A CBMs from different families were shown to bind to xyloglucan in solution with ligand binding driven by enthalpic changes. The nature of CBM-polysaccharide interactions is discussed.
authors.affiliation: Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Mercedes C
authors.initials: MC
authors.lastname: Hernandez-Gomez
authors.affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark.
authors.forename: Maja G
authors.initials: MG
authors.lastname: Rydahl
authors.affiliation: Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Artur
authors.initials: A
authors.lastname: Rogowski
authors.affiliation: Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Carl
authors.initials: C
authors.lastname: Morland
authors.affiliation: Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Alan
authors.initials: A
authors.lastname: Cartmell
authors.affiliation: Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Lucy
authors.initials: L
authors.lastname: Crouch
authors.affiliation: Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Aurore
authors.initials: A
authors.lastname: Labourel
authors.affiliation: CIISA - Faculdade de Medicina Veterinária, Universidade de Lisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal.
authors.forename: Carlos M G A
authors.initials: CM
authors.lastname: Fontes
authors.affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark.
authors.forename: William G T
authors.initials: WG
authors.lastname: Willats
authors.affiliation: Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK. Electronic address: harry.gilbert@newcastle.ac.uk.
authors.forename: Harry J
authors.initials: HJ
authors.lastname: Gilbert
authors.affiliation: Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK. Electronic address: j.p.knox@leeds.ac.uk.
authors.forename: J Paul
authors.initials: JP
authors.lastname: Knox
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D002473:Cell Wall / Q000378:metabolism; D002482:Cellulose / Q000737:chemistry* / Q000378:metabolism*; D048013:Acetivibrio thermocellus; D005936:Glucans / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D012995:Solubility; D014990:Xylans / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; C080369:CipA protein, Clostridium; D005936:Glucans; D008565:Membrane Proteins; D014990:Xylans; C029353:xyloglucan; D002482:Cellulose
keywords: CBM3a; Carbohydrate-binding module; Crystalline cellulose; Plant cell wall; Xyloglucan