title: From soil to structure, a novel dimeric β-glucosidase belonging to glycoside hydrolase family 3 isolated from compost using metagenomic analysis.
abstract: A recent metagenomic analysis sequenced a switchgrass-adapted compost community to identify enzymes from microorganisms that were specifically adapted to switchgrass under thermophilic conditions. These enzymes are being examined as part of the pretreatment process for the production of "second-generation" biofuels. Among the enzymes discovered was JMB19063, a novel three-domain β-glucosidase that belongs to the GH3 (glycoside hydrolase 3) family. Here, we report the structure of JMB19063 in complex with glucose and the catalytic variant D261N crystallized in the presence of cellopentaose. JMB19063 is first structure of a dimeric member of the GH3 family, and we demonstrate that dimerization is required for catalytic activity. Arg-587 and Phe-598 from the C-terminal domain of the opposing monomer are shown to interact with bound ligands in the D261N structure. Enzyme assays confirmed that these residues are absolutely essential for full catalytic activity.
authors.affiliation: Joint BioEnergy Institute, Emeryville, California 94608, USA.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: McAndrew
authors.forename: Joshua I
authors.initials: JI
authors.lastname: Park
authors.forename: Richard A
authors.initials: RA
authors.lastname: Heins
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Reindl
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Friedland
authors.forename: Patrik
authors.initials: P
authors.lastname: D'haeseleer
authors.forename: Trent
authors.initials: T
authors.lastname: Northen
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Sale
authors.forename: Blake A
authors.initials: BA
authors.lastname: Simmons
authors.forename: Paul D
authors.initials: PD
authors.lastname: Adams
mesh_terms: D005947:Glucose / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D054892:Metagenome; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012987:Soil; D012988:Soil Microbiology; D001617:beta-Glucosidase / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism
chemical_list: D012987:Soil; D001617:beta-Glucosidase; D005947:Glucose
keywords: Bacterial Metabolism; Biofuel; Cellulase; Enzyme Kinetics; Structural Biology; β-Glucosidase