曲霉属 GH2 β-甘露糖苷酶的系统发育分析及底物特异性。
Phylogenetic analysis and substrate specificity of GH2 β-mannosidases from Aspergillus species.
机构信息
Department of Biochemistry and Structural Biology, Lund University, Lund S-22100, Sweden.
出版信息
FEBS Lett. 2013 Nov 1;587(21):3444-9. doi: 10.1016/j.febslet.2013.08.029. Epub 2013 Sep 7.
Phylogenetic analysis of glycoside hydrolase family 2 including Aspergillus sequences and characterised β-mannosidases from other organisms, clusters putative Aspergillus β-mannosidases in two distinct clades (A and B). Aspergillus species have at least one paralog in each of the two clades. It appears that clade A members are extracellular and clade B members intracellular. Substrate specificity analysis of MndA of Aspergillus niger (clade A) and MndB of Aspergillus nidulans (clade B) show that MndB, in contrast to MndA, does not hydrolyse polymeric mannan and has probably evolved to hydrolyse small unbranched β-mannosides like mannobiose. A 3D-model of MndB provides further insight.
对包括曲霉属序列在内的糖苷水解酶家族 2 的系统发育分析，以及对其他生物的特征β-甘露糖苷酶进行了分析，将推测的曲霉属β-甘露糖苷酶聚类为两个不同的分支（A 和 B）。在这两个分支中，每个分支都至少有一个旁系同源物。似乎 A 分支成员是细胞外的，而 B 分支成员是细胞内的。对黑曲霉（A 分支）的 MndA 和构巢曲霉（B 分支）的 MndB 的底物特异性分析表明，MndB 与 MndA 不同，不能水解聚合甘露聚糖，并且可能已经进化为水解小分子无分支β-甘露糖苷，如甘露二糖。MndB 的 3D 模型提供了进一步的见解。
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