کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
3426592 1227337 2007 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mutational analysis of a helicase motif-based RNA 5′-triphosphatase/NTPase from bamboo mosaic virus
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی ویروس شناسی
پیش نمایش صفحه اول مقاله
Mutational analysis of a helicase motif-based RNA 5′-triphosphatase/NTPase from bamboo mosaic virus
چکیده انگلیسی

The helicase-like domain of BaMV replicase possesses NTPase and RNA 5′-triphosphatase activities. In this study, mutational effects of the helicase signature motifs and residue L543 on the two activities were investigated. Either activity was inactivated by K643A-S644A, D702A, D730A, R855A, or L543P mutations. On the other hand, Q826A, D858A and L543A had activities, in terms of kcat/Km, reduced by 5- to 15-fold. AMPPNP, a nonhydrolyzable ATP analogue, competitively inhibited RNA 5′-triphosphatase activity. Analogies of mutational effects on the two activities and approximation of Ki(AMPPNP) and Km(ATP) suggest that the catalytic sites of the activities are overlapped. Mutational effects on the viral accumulation in Chenopodium quinoa indicated that the activities manifested by the domain are required for BaMV survival. Results also suggest that Q826 in motif V plays an additional role in preventing tight binding to ATP, which would otherwise decrease further RNA 5′-triphosphatase, leading to demise of the virus in plant.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Virology - Volume 367, Issue 1, 10 October 2007, Pages 41–50
نویسندگان
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