کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2187369 1096113 2008 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structural Basis for Natural Lactonase and Promiscuous Phosphotriesterase Activities
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Structural Basis for Natural Lactonase and Promiscuous Phosphotriesterase Activities
چکیده انگلیسی

Organophosphates are the largest class of known insecticides, several of which are potent nerve agents. Consequently, organophosphate-degrading enzymes are of great scientific interest as bioscavengers and biodecontaminants. Recently, a hyperthermophilic phosphotriesterase (known as SsoPox), from the Archaeon Sulfolobus solfataricus, has been isolated and found to possess a very high lactonase activity. Here, we report the three-dimensional structures of SsoPox in the apo form (2.6 Å resolution) and in complex with a quorum-sensing lactone mimic at 2.0 Å resolution. The structure also reveals an unexpected active site topology, and a unique hydrophobic channel that perfectly accommodates the lactone substrate. Structural and mutagenesis evidence allows us to propose a mechanism for lactone hydrolysis and to refine the catalytic mechanism established for phosphotriesterases. In addition, SsoPox structures permit the correlation of experimental lactonase and phosphotriesterase activities and this strongly suggests lactonase activity as the cognate function of SsoPox. This example demonstrates that promiscuous activities probably constitute a large and efficient reservoir for the creation of novel catalytic activities.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Biology - Volume 379, Issue 5, 20 June 2008, Pages 1017–1028
نویسندگان
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