X-ray crystallographic native sulfur SAD structure determination of laminarinase Lam16A from Phanerochaete chrysosporium.
X-ray crystallographic native sulfur SAD structure determination of laminarinase Lam16A from Phanerochaete chrysosporium.
复制标题
DOI：
10.1107/s0907444906036407
复制
发表时间：
2006-11
期刊：
影响因子：
--
通讯作者：
J. Vasur;R. Kawai;A. Larsson;K. Igarashi;M. Sandgren;M. Samejima;J. Ståhlberg
中科院分区：
文献类型：
--
作者：
J. Vasur;R. Kawai;A. Larsson;K. Igarashi;M. Sandgren;M. Samejima;J. Ståhlberg
在毕赤酵母中重组表达来自黄孢原毛平革菌的海带酶Lam 16 A，结晶，并使用天然硫SAD X射线晶体学以1.34 A分辨率解析结构。它是来自糖苷水解酶家族16（GH 16）的非特异性1，3（4）-β-D-葡聚糖酶的第一个结构。黄孢原毛平革菌（P. chrysosporium）是一种降解木材的担子菌，Lam 16 A是海带多糖作为唯一碳源时表达的主要胞外蛋白。该蛋白折叠成与其他已知的GH 16酶结构（特别是来自Pseudoalteromonas carrageenovora的κ-角叉菜胶酶和来自Zobelia galactanivorans的β-琼脂酶）同源的弯曲的β-夹心。与相关的糖苷水解酶家族7（GH 7）酶的显著相似性也是明显的。哺乳动物凝集素，p58/ERGIC，以及多糖裂解酶（PL 7）酶也显示出显着的相似性Lam 16 A。该酶具有两个潜在的N-糖基化位点。一个这样的网站，在Asn 43，显示一个分支的七糖充分稳定，从X-射线衍射数据进行解释。发现另一个N-糖基化基序靠近催化中心，显然没有糖基化。
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.