5T4A

Crystal structure of BhGH81 in complex with laminaro-hexaose

Summary for 5T4A

• Entry DOI: 10.2210/pdb5t4a/pdb
• Related: 5T49 5T4C 5T4G
• Descriptor: Glycoside Hydrolase, beta-D-glucopyranose-(1-3)-alpha-D-glucopyranose, beta-D-glucopyranose-(1-3)-beta-D-glucopyranose-(1-3)-beta-D-glucopyranose, ... (6 entities in total)
• Functional Keywords: (alpha/beta)6 barrel, glycoside hydrolase, hydrolase
• Biological source: Bacillus halodurans
• Total number of polymer chains: 1
• Total formula weight: 89792.76

Authors

Pluvinage, B.,Boraston, A.B. (deposition date: 2016-08-29, release date: 2017-06-28, Last modification date: 2023-10-04)

Primary citation

Pluvinage, B.,Fillo, A.,Massel, P.,Boraston, A.B.
Structural Analysis of a Family 81 Glycoside Hydrolase Implicates Its Recognition of beta-1,3-Glucan Quaternary Structure.
Structure, 25:1348-1359.e3, 2017

PubMed Abstract: Family 81 glycoside hydrolases (GHs), which are known to cleave β-1,3-glucans, are found in archaea, bacteria, eukaryotes, and viruses. Here we examine the structural and functional features of the GH81 catalytic module, BhGH81, from the Bacillus halodurans protein BH0236 to probe the molecular basis of β-1,3-glucan recognition and cleavage. BhGH81 displayed activity on laminarin, curdlan, and pachyman, but not scleroglucan; the enzyme also cleaved β-1,3-glucooligosaccharides as small as β-1,3-glucotriose. The crystal structures of BhGH81 in complex with various β-1,3-glucooligosaccharides revealed distorted sugars in the -1 catalytic subsite and an arrangement consistent with an inverting catalytic mechanism having a proposed conformational itinerary of S → B → S. Notably, the architecture of the catalytic site, location of an adjacent ancillary β-1,3-glucan binding site, and the surface properties of the enzyme indicate the likely ability to recognize the double and/or triple-helical quaternary structures adopted by β-1,3-glucans.

PubMed: 28781080
DOI: 10.1016/j.str.2017.06.019

Experimental method

X-RAY DIFFRACTION (2.1 Å)