title: A CBM20 low-affinity starch-binding domain from glucan, water dikinase.
abstract: The family 20 carbohydrate-binding module (CBM20) of the Arabidopsis starch phosphorylator glucan, water dikinase 3 (GWD3) was heterologously produced and its properties were compared to the CBM20 from a fungal glucoamylase (GA). The GWD3 CBM20 has 50-fold lower affinity for cyclodextrins than that from GA. Homology modelling identified possible structural elements responsible for this weak binding of the intracellular CBM20. Differential binding of fluorescein-labelled GWD3 and GA modules to starch granules in vitro was demonstrated by confocal laser scanning microscopy and yellow fluorescent protein-tagged GWD3 CBM20 expressed in tobacco confirmed binding to starch granules in planta.
authors.affiliation: VKR Research Centre, Pro-Active Plants, Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: Camilla
authors.initials: C
authors.lastname: Christiansen
authors.forename: Maher Abou
authors.initials: MA
authors.lastname: Hachem
authors.forename: Mikkel A
authors.initials: MA
authors.lastname: Glaring
authors.forename: Anders
authors.initials: A
authors.lastname: Viksø-Nielsen
authors.forename: Bent W
authors.initials: BW
authors.lastname: Sigurskjold
authors.forename: Birte
authors.initials: B
authors.lastname: Svensson
authors.forename: Andreas
authors.initials: A
authors.lastname: Blennow
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001234:Aspergillus niger / Q000201:enzymology / Q000235:genetics; D003505:Cyclodextrins / Q000737:chemistry; D003594:Cytoplasmic Granules / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005087:Glucan 1,4-alpha-Glucosidase / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal / Q000379:methods; D017866:Phosphotransferases (Paired Acceptors) / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D013213:Starch / Q000235:genetics / Q000378:metabolism*; D040681:Structural Homology, Protein; D014026:Nicotiana / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D003505:Cyclodextrins; D005656:Fungal Proteins; D013213:Starch; D017866:Phosphotransferases (Paired Acceptors); C500668:alpha-glucan, water dikinase, Arabidopsis; D005087:Glucan 1,4-alpha-Glucosidase