5C5G

Crystal Structure of Aspergillus clavatus Sph3

5C5G の概要

• エントリーDOI: 10.2210/pdb5c5g/pdb
• 分子名称: spherulin-4, 1,2-ETHANEDIOL (3 entities in total)
• 機能のキーワード: spherulin, (beta/alpha) barrel, glycoside hydrolase, hydrolase
• 由来する生物種: Aspergillus clavatus
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28379.07

構造登録者

Bamford, N.C.,Little, D.J.,Howell, P.L. (登録日: 2015-06-19, 公開日: 2015-09-16, 最終更新日: 2024-10-16)

主引用文献

Bamford, N.C.,Snarr, B.D.,Gravelat, F.N.,Little, D.J.,Lee, M.J.,Zacharias, C.A.,Chabot, J.C.,Geller, A.M.,Baptista, S.D.,Baker, P.,Robinson, H.,Howell, P.L.,Sheppard, D.C.
Sph3 Is a Glycoside Hydrolase Required for the Biosynthesis of Galactosaminogalactan in Aspergillus fumigatus.
J.Biol.Chem., 290:27438-27450, 2015

PubMed Abstract: Aspergillus fumigatus is the most virulent species within the Aspergillus genus and causes invasive infections with high mortality rates. The exopolysaccharide galactosaminogalactan (GAG) contributes to the virulence of A. fumigatus. A co-regulated five-gene cluster has been identified and proposed to encode the proteins required for GAG biosynthesis. One of these genes, sph3, is predicted to encode a protein belonging to the spherulin 4 family, a protein family with no known function. Construction of an sph3-deficient mutant demonstrated that the gene is necessary for GAG production. To determine the role of Sph3 in GAG biosynthesis, we determined the structure of Aspergillus clavatus Sph3 to 1.25 Å. The structure revealed a (β/α)8 fold, with similarities to glycoside hydrolase families 18, 27, and 84. Recombinant Sph3 displayed hydrolytic activity against both purified and cell wall-associated GAG. Structural and sequence alignments identified three conserved acidic residues, Asp-166, Glu-167, and Glu-222, that are located within the putative active site groove. In vitro and in vivo mutagenesis analysis demonstrated that all three residues are important for activity. Variants of Asp-166 yielded the greatest decrease in activity suggesting a role in catalysis. This work shows that Sph3 is a glycoside hydrolase essential for GAG production and defines a new glycoside hydrolase family, GH135.

PubMed: 26342082
DOI: 10.1074/jbc.M115.679050

実験手法

X-RAY DIFFRACTION (1.248 Å)