title: X-ray crystallographic native sulfur SAD structure determination of laminarinase Lam16A from Phanerochaete chrysosporium.
abstract: Laminarinase Lam16A from Phanerochaete chrysosporium was recombinantly expressed in Pichia pastoris, crystallized and the structure was solved at 1.34 A resolution using native sulfur SAD X-ray crystallography. It is the first structure of a non-specific 1,3(4)-beta-D-glucanase from glycoside hydrolase family 16 (GH16). P. chrysosporium is a wood-degrading basidiomycete fungus and Lam16A is the predominant extracellular protein expressed when laminarin is used as the sole carbon source. The protein folds into a curved beta-sandwich homologous to those of other known GH16 enzyme structures (especially kappa-carrageenase from Pseudoalteromonas carrageenovora and beta-agarase from Zobelia galactanivorans). A notable likeness is also evident with the related glycoside hydrolase family 7 (GH7) enzymes. A mammalian lectin, p58/ERGIC, as well as polysaccharide lyase (PL7) enzymes also showed significant similarity to Lam16A. The enzyme has two potential N-glycosylation sites. One such site, at Asn43, displayed a branched heptasaccharide sufficiently stabilized to be interpreted from the X-ray diffraction data. The other N-glycosylation motif was found close to the catalytic centre and is evidently not glycosylated.
authors.affiliation: Department of Molecular Biology, Swedish University of Agricultural Sciences, PO Box 590, SE-75124 Uppsala, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Vasur
authors.forename: Rie
authors.initials: R
authors.lastname: Kawai
authors.forename: Anna M
authors.initials: AM
authors.lastname: Larsson
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Igarashi
authors.forename: Mats
authors.initials: M
authors.lastname: Sandgren
authors.forename: Masahiro
authors.initials: M
authors.lastname: Samejima
authors.forename: Jerry
authors.initials: J
authors.lastname: Ståhlberg
mesh_terms: D020134:Catalytic Domain; D018360:Crystallography, X-Ray / Q000379:methods; D044644:Endo-1,3(4)-beta-Glucanase / Q000737:chemistry* / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics; D015870:Gene Expression; D005936:Glucans; D006031:Glycosylation; D006801:Humans; D037241:Mannose-Binding Lectins / Q000737:chemistry / Q000235:genetics; D020075:Phanerochaete / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D010843:Pichia / Q000235:genetics / Q000254:growth & development; D011134:Polysaccharides / Q000494:pharmacology; D046188:Protein Modification, Translational; D017434:Protein Structure, Tertiary
chemical_list: D005656:Fungal Proteins; D005936:Glucans; D037241:Mannose-Binding Lectins; D011134:Polysaccharides; C008247:laminaran; D044644:Endo-1,3(4)-beta-Glucanase