The structure of PfGH50B, an agarase from the marine bacterium Pseudoalteromonas fuliginea PS47

Acta Crystallogr F Struct Biol Commun. 2020 Sep 1;76(Pt 9):422-427. doi: 10.1107/S2053230X20010328. Epub 2020 Aug 19.

Abstract

The recently identified marine bacterium Pseudoalteromonas fuliginea sp. PS47 possesses a polysaccharide-utilization locus dedicated to agarose degradation. In particular, it contains a gene (locus tag EU509_06755) encoding a β-agarase that belongs to glycoside hydrolase family 50 (GH50), PfGH50B. The 2.0 Å resolution X-ray crystal structure of PfGH50B reveals a rare complex multidomain fold that was found in two of the three previously determined GH50 structures. The structure comprises an N-terminal domain with a carbohydrate-binding module (CBM)-like fold fused to a C-terminal domain by a rigid linker. The CBM-like domain appears to function by extending the catalytic groove of the enzyme. Furthermore, the PfGH50B structure highlights key structural features in the mobile loops that may function to restrict the degree of polymerization of the neoagaro-oligosaccharide products and the enzyme processivity.

Keywords: agarase; agarose; glycoside hydrolase; marine bacterium; neoagaro-oligosaccharides.

MeSH terms

  • Amino Acid Sequence
  • Aquatic Organisms / chemistry
  • Aquatic Organisms / enzymology
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Catalytic Domain
  • Cloning, Molecular
  • Crystallography, X-Ray
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Gene Expression
  • Genetic Vectors / chemistry
  • Genetic Vectors / metabolism
  • Glycoside Hydrolases / chemistry*
  • Glycoside Hydrolases / genetics
  • Glycoside Hydrolases / metabolism
  • Models, Molecular
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Interaction Domains and Motifs
  • Pseudoalteromonas / chemistry*
  • Pseudoalteromonas / enzymology
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sepharose / chemistry*
  • Sepharose / metabolism

Substances

  • Bacterial Proteins
  • Recombinant Proteins
  • Sepharose
  • Glycoside Hydrolases
  • agarase

Supplementary concepts

  • Pseudoalteromonas fuliginea