title: Parallel beta/alpha-barrels of alpha-amylase, cyclodextrin glycosyltransferase and oligo-1,6-glucosidase versus the barrel of beta-amylase: evolutionary distance is a reflection of unrelated sequences.
abstract: The structures of functionally related beta/alpha-barrel starch hydrolases, alpha-amylase, beta-amylase, cyclodextrin glycosyltransferase and oligo-1,6-glucosidase, are discussed, their mutual sequence similarities being emphasized. Since these enzymes (except for beta-amylase) along with the predicted set of more than ten beta/alpha-barrels from the alpha-amylase enzyme superfamily fulfil the criteria characteristic of the products of divergent evolution, their unrooted distance tree is presented.
authors.affiliation: Institute of Ecobiology, Slovak Academy of Sciences, Bratislava.
authors.forename: S
authors.initials: S
authors.lastname: Janecek
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D005075:Biological Evolution; D017124:Conserved Sequence; D005964:Glucosyltransferases / Q000737:chemistry*; D008969:Molecular Sequence Data; D009834:Oligo-1,6-Glucosidase / Q000737:chemistry*; D000516:alpha-Amylases / Q000737:chemistry*; D001614:beta-Amylase / Q000737:chemistry*
chemical_list: D005964:Glucosyltransferases; C019963:cyclomaltodextrin glucanotransferase; D000516:alpha-Amylases; D009834:Oligo-1,6-Glucosidase; D001614:beta-Amylase