Here we describe the first crystal structure of a beta-1,4-endoglucanase from a brown-rot fungus, Gloeophyllum trabeum GtCel45A, which belongs to subfamily C of glycoside hydrolase family 45 (GH45). GtCel45A is ~ 18 kDa in size and the crystal structure contains 179 amino acids. The structure is refined at 1.30 Å resolution and R_free 0.18. The enzyme consists of a single catalytic module folded into a six-stranded double-psi beta-barrel domain surrounded by long loops. GtCel45A is very similar in sequence (82% identity) and structure to PcCel45A from the white-rot fungus Phanerochaete chrysosporium. Surprisingly though, initial hydrolysis of barley beta-glucan was almost twice as fast in GtCel45A as compared to PcCel45A.

中文翻译：

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褐腐真菌 Gloeophyllum trabeum GtCel45A 家族 45 糖苷水解酶的第一个晶体结构

在这里，我们描述了来自褐腐真菌Gloeophyllum trabeum Gt Cel45A 的 β-1,4-内切葡聚糖酶的第一个晶体结构，该真菌属于糖苷水解酶家族 45 (GH45) 的 C 亚科。Gt Cel45A 大小约为 18 kDa，晶体结构包含 179 个氨基酸。该结构以 1.30 Å 分辨率和R _free 0.18 进行精修。该酶由折叠成由长环包围的六链双 psi β 桶结构域的单个催化模块组成。Gt Cel45A 在序列（82% 同一性）和结构上与来自白腐真菌Phanerochaete chrysosporium的Pc Cel45A非常相似。但令人惊讶的是， Gt Cel45A中大麦 β-葡聚糖的初始水解速度几乎是Pc Cel45A 的两倍。