کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5511684 | 1540214 | 2017 | 35 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
S-adenosyl-L-homocysteine hydrolase from a hyperthermophile (Thermotoga maritima) is expressed in Escherichia coli in inactive form - Biochemical and structural studies
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کلمات کلیدی
DLSoxidized form of nicotinamide adenine dinucleotideS-adenosyl-l-homocysteineSAHHcymPDADPPMSFl-homocysteineITCSAMADOSECHEPESFPLCAMP(4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) - (4- (2-hydroxyethyl) -1-piperazineethanesulfonic acid)2-(N-morpholino)ethanesulfonic acid - 2- (N-مورفولینو) اتان سولفونیک اسید2-methyl-2,4-pentanediol - 2-متیل-2،4-پنتانیدیولNAD+ - NAD +S-adenosyl-L-homocysteine hydrolase - S-adenosyl-L-homocysteine hydrolaseS-adenosyl-L-methionine - S-adenosyl-L-metioninetris(2-carboxyethyl)phosphine - tris (2-carboxyethyl) فسفینAdenosine - آدنوزینadenosine 5′-monophosphate - آدنوزین 5'-مونوفسفرهX-ray crystallography - بلورنگاری پرتو-ایکسTev - به توTCEP - ساکتfast protein liquid chromatography - سریع کروماتوگرافی مایع پروتئینreduced form of nicotinamide adenine dinucleotide - فرم کاهش یافته از نیکوتین آمید آدنین دینکلوتیدphenylmethylsulfonyl fluoride - فنیل متیل سولفونیل فلورایدMeS - مسNADH - نادانTobacco etch virus - ویروس تنباکو اچatomic displacement parameter - پارامتر جابجایی اتمیDynamic Light Scattering - پراکندگی نور دینامیکیIsothermal titration calorimetry - کالری سنجی تیتاسیون ایزوترمالSize exclusion chromatography - کروماتوگرافی اندازهای طردی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
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چکیده انگلیسی
Thermotoga maritima is a hyperthermophilic bacterium but its genome encodes a number of archaeal proteins including S-adenosyl-L-homocysteine hydrolase (SAHase), which regulates cellular methylation reactions. The question of proper folding and activity of proteins of extremophilic origin is an intriguing problem. When expressed in E.coli and purified (as a homotetramer) at room temperature, the hyperthermophilic SAHase from T.maritima was inactive. ITC study indicated that the protein undergoes heat-induced conformational changes, and enzymatic activity assays demonstrated that these changes are required to attain enzymatic activity. To explain the mechanism of thermal activation, two crystal structures of the inactive form of T. maritima SAHase (iTmSAHase) were determined for an incomplete binary complex with the reduced cofactor (NADH), and in a mixture of binary complexes with NADH and with adenosine. In contrast to active SAHases, in iTmSAHase only two of the four subunits contain a bound cofactor, predominantly in its non-reactive, reduced state. Moreover, the closed-like conformation of the cofactor-containing subunits precludes substrate delivery to the active site. The two other subunits cannot be involved in the enzymatic reaction either; although they have an open-like conformation, they do not contain the cofactor, whose binding site may be occupied by an adenosine molecule. The results suggest that this enzyme, when expressed in mesophilic cells, is arrested in the activity-incompatible conformation revealed by its crystal structures.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Biological Macromolecules - Volume 104, Part A, November 2017, Pages 584-596
Journal: International Journal of Biological Macromolecules - Volume 104, Part A, November 2017, Pages 584-596
نویسندگان
Krzysztof Brzezinski, Justyna Czyrko, Joanna Sliwiak, Edyta Nalewajko-Sieliwoniuk, Mariusz Jaskolski, Boguslaw Nocek, Zbigniew Dauter,