Glycosidic bond specificity of glucansucrases: on the role of acceptor substrate binding residues

Hans Leemhuis, Tjaard Pijning, Justyna M. Dobruchowska, Bauke W. Dijkstra, Lubbert Dijkhuizen*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

40 Citations (Scopus)
198 Downloads (Pure)

Abstract

Many lactic acid bacteria produce extracellular alpha-glucan polysaccharides using a glucansucrase and sucrose as glucose donor. The structure and the physicochemical properties of the alpha-glucans produced are determined by the nature of the glucansucrase. Typically, the alpha-glucans contain two types of alpha-glycosidic linkages, for example, (alpha 1-2), (alpha 1-3), (alpha 1-4) or (alpha 1-6), which may be randomly or regularly distributed. Usually, the alpha-glucan chains are also branched, which gives rise to an additional level of complexity. Even though the first crystal structure was reported in 2010, our current understanding of the structure-function relationships of glucansucrases is not advanced enough to predict the alpha-glucan specificity from the sequence alone. Nevertheless, based on sequence alignments and site-directed mutagenesis, a few amino acid residues have been identified as being important for the glycosidic bond specificity of glucansucrases. A new development in GH70 research was the identification of a cluster of alpha-glucan disproportionating enzymes. Here, we discuss the current insights into the structure-function relationships of GH70 enzymes in the light of the recently determined crystal structure of glucansucrases.

Original languageEnglish
Pages (from-to)366-376
Number of pages11
JournalBiocatalysis and Biotransformation
Volume30
Issue number3
DOIs
Publication statusPublished - May-2012

Keywords

  • alternansucrase
  • dextransucrase
  • glycoside hydrolase
  • reuteransucrase
  • lactic acid bacteria
  • protein engineering
  • ALPHA-AMYLASE FAMILY
  • AMINO-ACID-RESIDUES
  • STREPTOCOCCUS-MUTANS GLUCOSYLTRANSFERASES
  • LACTOBACILLUS-REUTERI
  • LEUCONOSTOC-MESENTEROIDES
  • DIRECTED EVOLUTION
  • CYCLODEXTRIN GLYCOSYLTRANSFERASE
  • GTF-I
  • MOLECULAR CHARACTERIZATION
  • CHEMOENZYMATIC SYNTHESIS

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