4BPZ: Crystal Structure Of Lama_e269s From Zobellia Galactanivorans In Complex With A Trisaccharide Of 1,3-1,4-beta-d-glucan

Laminarinase is commonly used to describe beta-1,3-glucanases widespread throughout Archaea, bacteria, and several eukaryotic lineages. Some beta-1,3-glucanases have already been structurally and biochemically characterized, but very few from organisms that are in contact with genuine laminarin, the storage polysaccharide of brown algae. Here we report the heterologous expression and subsequent biochemical and structural characterization of ZgLamAGH16 from Zobellia galactanivorans, the first GH16 laminarinase from a marine bacterium associated with seaweeds. ZgLamAGH16 contains a unique additional loop, compared with other GH16 laminarinases, which is composed of 17 amino acids and gives a bent shape to the active site cleft of the enzyme. This particular topology is perfectly adapted to the U-shaped conformation of laminarin chains in solution and thus explains the predominant specificity of ZgLamAGH16 for this substrate. The three-dimensional structure of the enzyme and two enzyme-substrate complexes, one with laminaritetraose and the other with a trisaccharide of 1,3-1,4-beta-d-glucan, have been determined at 1.5, 1.35, and 1.13 A resolution, respectively. The structural comparison of substrate recognition pattern between these complexes allows the proposition that ZgLamAGH16 likely diverged from an ancestral broad specificity GH16 beta-glucanase and evolved toward a bent active site topology adapted to efficient degradation of algal laminarin.
PDB ID: 4BPZDownload
MMDB ID: 116008
PDB Deposition Date: 2013/5/29
Updated in MMDB: 2013/12
Experimental Method:
x-ray diffraction
Resolution: 1.13  Å
Source Organism:
Similar Structures:
Biological Unit for 4BPZ: monomeric; determined by author and by software (PISA)
Molecular Components in 4BPZ
Label Count Molecule
Protein (1 molecule)
Endo-1,3-beta-glucanase, Family Gh16
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

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