کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6491101 | 43397 | 2015 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Corynebacterium glutamicum ATP-phosphoribosyl transferases suitable for l-histidine production - Strategies for the elimination of feedback inhibition
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بیو مهندسی (مهندسی زیستی)
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چکیده انگلیسی
l-Histidine biosynthesis in Corynebacterium glutamicum is mainly regulated by l-histidine feedback inhibition of the ATP-phosphoribosyltransferase HisG that catalyzes the first step of the pathway. The elimination of this feedback inhibition is the first and most important step in the development of an l-histidine production strain. For this purpose, a combined approach of random mutagenesis and rational enzyme redesign was performed. Mutants spontaneously resistant to the toxic l-histidine analog β-(2-thiazolyl)-dl-alanine (2-TA) revealed novel and unpredicted mutations in the C-terminal regulatory domain of HisG resulting in increased feedback resistance. Moreover, deletion of the entire C-terminal regulatory domain in combination with the gain of function mutation S143F in the catalytic domain resulted in a HisG variant that is still highly active even at l-histidine concentrations close to the solubility limit. Notably, the S143F mutation on its own provokes feedback deregulation, revealing for the first time an amino acid residue in the catalytic domain of HisG that is involved in the feedback regulatory mechanism. In addition, we investigated the effect of hisG mutations for l-histidine production on different levels. This comprised the analysis of different expression systems, including plasmid- and chromosome-based overexpression, as well as the importance of codon choice for HisG mutations. The combination of domain deletions, single amino acid exchanges, codon choice, and chromosome-based overexpression resulted in production strains accumulating around 0.5 g lâ1l-histidine, demonstrating the added value of the different approaches.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Biotechnology - Volume 206, 20 July 2015, Pages 26-37
Journal: Journal of Biotechnology - Volume 206, 20 July 2015, Pages 26-37
نویسندگان
Robert K. Kulis-Horn, Marcus Persicke, Jörn Kalinowski,