8J5M

Structure of GH1 Br2 beta-glucosidase E350G mutant from bovine rumen metagenome

Summary for 8J5M

• Entry DOI: 10.2210/pdb8j5m/pdb
• Related: 8J3M
• Descriptor: Beta-glucosidase, ACETATE ION, SULFATE ION, ... (4 entities in total)
• Functional Keywords: glycoside hydrolase, gh1, metagenome, beta-glucosidase, hydrolase
• Biological source: uncultured bacterium
• Total number of polymer chains: 4
• Total formula weight: 215768.20

Authors

Kaenying, W.,Kongsaeree, P.T.,Tagami, T. (deposition date: 2023-04-23, release date: 2023-11-22, Last modification date: 2024-01-03)

Primary citation

Kaenying, W.,Tagami, T.,Suwan, E.,Pitsanuwong, C.,Chomngam, S.,Okuyama, M.,Kongsaeree, P.,Kimura, A.,Kongsaeree, P.T.
Structural and mutational analysis of glycoside hydrolase family 1 Br2 beta-glucosidase derived from bovine rumen metagenome.
Heliyon, 9:e21923-e21923, 2023

PubMed Abstract: Ruminant animals rely on the activities of -glucosidases from residential microbes to convert feed fibers into glucose for further metabolic uses. In this report, we determined the structures of Br2, which is a glycoside hydrolase family 1 -glucosidase from the bovine rumen metagenome. Br2 folds into a classical (/)-TIM barrel domain but displays unique structural features at loop 5→5 and -helix 5, resulting in different positive subsites from those of other GH1 enzymes. Br2 exhibited the highest specificity toward laminaritriose, suggesting its involvement in -glucan hydrolysis in digested feed. We then substituted the residues at subsites +1 and + 2 of Br2 with those of -glucosidase. The C170E and C221T mutations provided favorable interactions with glucooligosaccharide substrates at subsite +2, while the A219N mutation probably improved the substrate preference for cellobiose and gentiobiose relative to laminaribiose at subsite +1. The N407Y mutation increased the affinity toward cellooligosaccharides. These results give further insights into the molecular determinants responsible for substrate specificity in GH1 -glucosidases and may provide a basis for future enzyme engineering applications.

PubMed: 38034805
DOI: 10.1016/j.heliyon.2023.e21923

Experimental method

X-RAY DIFFRACTION (1.621 Å)