title: Starch-synthase III family encodes a tandem of three starch-binding domains.
abstract: The starch-synthase III (SSIII), with a total of 1025 residues, is one of the enzymes involved in plants starch synthesis. SSIII from Arabidopsis thaliana contains a putative N-terminal transit peptide followed by a 557-amino acid SSIII-specific domain (SSIII-SD) with three internal repeats and a C-terminal catalytic domain of 450 amino acids. Here, using computational characterization techniques, we show that each of the three internal repeats encodes a starch-binding domain (SBD). Although the SSIII from A. thaliana and its close homologous proteins show no detectable sequence similarity with characterized SBD sequences, the amino acid residues known to be involved in starch binding are well conserved.
authors.affiliation: Centro de Estudios e Investigaciones, Universidad Nacional de Quilmes, Bernal, Argentina.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Palopoli
authors.forename: María Victoria
authors.initials: MV
authors.lastname: Busi
authors.forename: María Silvina
authors.initials: MS
authors.lastname: Fornasari
authors.forename: Diego
authors.initials: D
authors.lastname: Gomez-Casati
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Ugalde
authors.forename: Gustavo
authors.initials: G
authors.lastname: Parisi
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000737:chemistry*; D001483:Base Sequence; D001665:Binding Sites; D005964:Glucosyltransferases / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D020539:Sequence Analysis, Protein
chemical_list: D029681:Arabidopsis Proteins; D005964:Glucosyltransferases; C504530:starch synthase III, Arabidopsis