Plants exhibit a vast array of sesquiterpenes, C15 hydrocarbons which often function as herbivore-repellents or pollinator-attractants. These in turn are produced by a diverse range of sesquiterpene synthases. A comprehensive analysis of these enzymes in terms of product specificity has been hampered by the lack of a centralized resource of sufficient functionally annotated sequence data. To address this, we have gathered 262 plant sesquiterpene synthase sequences with experimentally characterized products. The annotated enzyme sequences allowed for an analysis of terpene synthase motifs, leading to the extension of one motif and recognition of a variant of another. In addition, putative terpene synthase sequences were obtained from various resources and compared with the annotated sesquiterpene synthases. This analysis indicated regions of terpene synthase sequence space which so far are unexplored experimentally. Finally, we present a case describing mutational studies on residues altering product specificity, for which we analyzed conservation in our database. This demonstrates an application of our database in choosing likely-functional residues for mutagenesis studies aimed at understanding or changing sesquiterpene synthase product specificity.

中文翻译：

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表征植物倍半萜合酶的分析

植物表现出大量的倍半萜烯、C15 碳氢化合物，它们通常用作食草动物的驱虫剂或传粉媒介的引诱剂。这些反过来又由各种倍半萜烯合酶产生。由于缺乏足够的功能注释序列数据的集中资源，在产品特异性方面对这些酶的综合分析受到阻碍。为了解决这个问题，我们收集了 262 个植物倍半萜烯合酶序列和实验表征的产品。注释的酶序列允许分析萜烯合酶基序，导致一个基序的延伸和另一个基序的变体的识别。此外，从各种资源中获得了推定的萜烯合酶序列，并与注释的倍半萜烯合酶进行了比较。该分析表明了迄今为止尚未通过实验探索的萜烯合酶序列空间区域。最后，我们介绍了一个案例，描述了关于改变产品特异性的残基的突变研究，我们分析了我们数据库中的保护性。这证明了我们的数据库在为旨在了解或改变倍半萜合酶产物特异性的诱变研究中选择可能具有功能的残基方面的应用。