کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10537961 | 962885 | 2005 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Two consecutive aspartic acid residues conferring herbicide resistance in tobacco acetohydroxy acid synthase
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کلمات کلیدی
AHASisopropyl-β-d-thiogalactosideGSTIPTGThDPGSHSite-directed mutagenesis - mutagenesis مواجه با سایتflavine adenine dinucleotide - آدنین دینوکلئوتید فلایینAcetohydroxy acid synthase - استاتو هیدروکسی اسید سنتازFAD - بدTobacco - توتون و تنباکوThiamine diphosphate - تیامین دی فسفاتcircular dichroism - رنگ تابی دورانیHerbicide resistance - مقاومت علف کشpolymerase chain reaction - واکنش زنجیره ای پلیمرازPCR - واکنش زنجیرهٔ پلیمرازGlutathione - گلوتاتیونglutathione S-transferase - گلوتاتیون S-ترانسفراز
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Acetohydroxy acid synthase (AHAS) catalyzes the first common step in the biosynthesis pathway of the branch chain amino acids in plants and microorganisms. A great deal of interest has been focused on AHAS since it was identified as the target of several classes of potent herbicides. In an effort to produce a mutant usable in the development of an herbicide-resistant transgenic plant, two consecutive aspartic acid residues, which are very likely positioned next to the enzyme-bound herbicide sulfonylurea as the homologous residues in AHAS from yeast, were selected for this study. Four single-point mutants and two double mutants were constructed, and designated D374A, D374E, D375A, D375E, D374A/D375A, and D374E/D375E. All mutants were active, but the D374A mutant exhibited substrate inhibition at high concentrations. The D374E mutant also evidenced a profound reduction with regard to catalytic efficiency. The mutation of D375A increased the Km value for pyruvate nearly 10-fold. In contrast, the D375E mutant reduced this value by more than 3-fold. The double mutants exhibited synergistic reduction in catalytic efficiencies. All mutants constructed in this study proved to be strongly resistant to the herbicide sulfonylurea Londax. The double mutants and the mutants with the D375 residue were also strongly cross-resistant to the herbicide triazolopyrimidine TP. However, only the D374A mutant proved to be strongly resistant to imidazolinone Cadre. The data presented here indicate that the two residues, D374 and D375, are located at a common binding site for the herbicides sulfonylurea and triazolopyrimidine. D375E may be a valuable mutant for the development of herbicide-resistant transgenic plants.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics - Volume 1749, Issue 1, 20 May 2005, Pages 103-112
Journal: Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics - Volume 1749, Issue 1, 20 May 2005, Pages 103-112
نویسندگان
Dung Tien Le, Moon-Young Yoon, Young Tae Kim, Jung-Do Choi,