کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2052116 1074221 2006 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mapping active site residues in glutamate-5-kinase. The substrate glutamate and the feed-back inhibitor proline bind at overlapping sites
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
Mapping active site residues in glutamate-5-kinase. The substrate glutamate and the feed-back inhibitor proline bind at overlapping sites
چکیده انگلیسی

Glutamate-5-kinase (G5K) catalyzes the controlling first step of proline biosynthesis. Substrate binding, catalysis and feed-back inhibition by proline are functions of the N-terminal ∼260-residue domain of G5K. We study here the impact on these functions of 14 site-directed mutations affecting 9 residues of Escherichia coli G5K, chosen on the basis of the structure of the bisubstrate complex of the homologous enzyme acetylglutamate kinase (NAGK). The results support the predicted roles of K10, K217 and T169 in catalysis and ATP binding and of D150 in orienting the catalytic lysines. They support the implication of D148 and D150 in glutamate binding and of D148 and N149 in proline binding. Proline increases the S0.5 for glutamate and appears to bind at a site overlapping with the site for glutamate. We conclude that G5K and NAGK closely resemble each other concerning substrate binding and catalysis, but that they have different mechanisms of feed-back control.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: FEBS Letters - Volume 580, Issue 26, 13 November 2006, Pages 6247–6253
نویسندگان
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