From Soil to Structure, a Novel Dimeric β-Glucosidase Belonging to Glycoside Hydrolase Family 3 Isolated from Compost Using Metagenomic Analysis
From Soil to Structure, a Novel Dimeric β-Glucosidase Belonging to Glycoside Hydrolase Family 3 Isolated from Compost Using Metagenomic Analysis
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DOI：
10.1074/jbc.m113.458356
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发表时间：
2013-05-24
影响因子：
4.8
通讯作者：
Adams, Paul D.
中科院分区：
文献类型：
--
作者：
McAndrew, Ryan P.;Park, Joshua I.;Adams, Paul D.
最近的一项宏基因组分析对一种适应柳枝稷的堆肥群落进行了测序，以鉴定出在嗜热条件下特别适应柳枝稷的微生物酶。这些酶正在作为生产“第二代”生物燃料的预处理过程的一部分进行研究。其中发现的酶是JMB19063，这是一种新的三结构域β -葡萄糖苷酶，属于GH3（糖苷水解酶3）家族。在这里，我们报道了JMB19063与葡萄糖配合物的结构，以及催化变体D261N在纤维素戊糖存在下结晶。JMB19063是GH3家族二聚体成员的第一个结构，我们证明了二聚化是催化活性所必需的。相反单体c端结构域的Arg-587和ph -598与D261N结构中的结合配体相互作用。酶分析证实这些残基对于充分的催化活性是绝对必要的。
A recent metagenomic analysis sequenced a switchgrass-adapted compost community to identify enzymes from microorganisms that were specifically adapted to switchgrass under thermophilic conditions. These enzymes are being examined as part of the pretreatment process for the production of "second-generation" biofuels. Among the enzymes discovered was JMB19063, a novel three-domain beta-glucosidase that belongs to the GH3 (glycoside hydrolase 3) family. Here, we report the structure of JMB19063 in complex with glucose and the catalytic variant D261N crystallized in the presence of cellopentaose. JMB19063 is first structure of a dimeric member of the GH3 family, and we demonstrate that dimerization is required for catalytic activity. Arg-587 and Phe-598 from the C-terminal domain of the opposing monomer are shown to interact with bound ligands in the D261N structure. Enzyme assays confirmed that these residues are absolutely essential for full catalytic activity.