5NS7

Crystal structure of beta-glucosidase BglM-G1 mutant H75R from marine metagenome

Summary for 5NS7

• Entry DOI: 10.2210/pdb5ns7/pdb
• Descriptor: beta-glucosidase M - G1, SULFATE ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: hydrolase, beta-glucosidase, metagenomes
• Biological source: marine metagenome
• Total number of polymer chains: 3
• Total formula weight: 157866.46

Authors

Mhaindarkar, D.C.,Gasper, R.,Lupilova, N.,Leichert, L.I.,Hofmann, E. (deposition date: 2017-04-25, release date: 2018-08-08, Last modification date: 2024-05-08)

Primary citation

Mhaindarkar, D.,Gasper, R.,Lupilov, N.,Hofmann, E.,Leichert, L.I.
Loss of a conserved salt bridge in bacterial glycosyl hydrolase BgIM-G1 improves substrate binding in temperate environments.
Commun Biol, 1:171-171, 2018

PubMed Abstract: Salt bridges are the strongest electrostatic interactions in proteins. They substantially contribute to a protein's structural stability. Thus, mutations of salt bridges are typically selected against. Here, we report on the evolutionary loss of a highly conserved salt bridge in the GH1 family glycosyl hydrolase BglM-G1. BglM-G1's gene was found in the bacterial metagenome of a temperate, seasonally cold marine habitat. In BglM-G1, arginine 75 is replaced by a histidine. While fully retaining β-glucosidase activity, BglM-G1 is less heat stable than an H75R variant, in which the salt bridge was artificially re-introduced. However, the toward its substrates was lower in wild type, leading to an overall higher catalytic efficiency. Our results indicate that this loss of the salt bridge leads to higher flexibility in BglM-G1's active site, trading structural stability at high temperatures, a trait not needed in a temperate, seasonally cold habitat, for a more effective catalytic activity.

PubMed: 30345395
DOI: 10.1038/s42003-018-0167-7

Experimental method

X-RAY DIFFRACTION (1.54 Å)