Starch- and glycogen-debranching and branching enzymes: Prediction of structural features of the catalytic (β/α)8-barrel domain and evolutionary relationship to other amylolytic enzymes

Hans M. Jespersen, E. Ann MacGregor, Bernard Henrissat, Michael R. Sierks, Birte Svensson

Research output: Contribution to journalArticle

216 Scopus citations


Sequence alignment and structure prediction are used to locate catalytic α-amylase-type (β/α)8-barrel domains and the positions of their β-strands and α-helices in isoamylase, pullulanase, neopullulanase, α-amylase-pullulanase, dextran glucosidase, branching enzyme, and glycogen branching enzymes-all enzymes involved in hydrolysis or synthesis of α-1,6-glucosidic linkages in starch and related polysaccharides. This has allowed identification of the transferase active site of the glycogen debranching enzyme and the locations of β {upwards double arrow} α loops making up the active sites of all enzymes studied. Activity and specificity of the enzymes are discussed in terms of conserved amino acid residues and loop variations. An evolutionary distance tree of 47 amylolytic and related enzymes is built on 37 residues representing the four best conserved β-strands of the barrel. It exhibits clusters of enzymes close in specificity, with the branching and glycogen debranching enzymes being the most distantly related.

Original languageEnglish (US)
Pages (from-to)791-805
Number of pages15
JournalJournal of Protein Chemistry
Issue number6
StatePublished - Dec 1 1993



  • amylolytic enzymes
  • evolutionary tree
  • sequence comparison
  • structure prediction
  • α-1,6-Glucosidic bond metabolism

ASJC Scopus subject areas

  • Biochemistry

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