tailieunhanh - Báo cáo khoa học: Structural basis for the changed substrate specificity of Drosophila melanogaster deoxyribonucleoside kinase mutant N64D

TheDrosophila melanogasterdeoxyribonucleoside kinase (Dm-dNK) double mutant N45D⁄N64D was identified during a previous directed evolution study. This mutant enzyme had a decreased activity towards the natural substrates and decreased feedback inhibition with dTTP, whereas the activ-ity with 3¢-modified nucleoside analogs like 3¢-azidothymidine (AZT) was nearly unchanged. | ềFEBS Journal Structural basis for the changed substrate specificity of Drosophila melanogaster deoxyribonucleoside kinase mutant N64D Martin Welin1 Tine Skovgaard2 Wolfgang Knecht3 Chunying Zhu2 Dvora Berenstein2 Birgitte Munch-Petersen2 Jure PiSkur3 t and Hans Eklund1 1 Department of Molecular Biology Swedish University of AgriculturalSciences BiomedicalCenter Uppsala Sweden 2 Department of Life Sciences and Chemistry Roskilde University Denmark 3 BioCentrum-DTU TechnicalUniversity of Denmark Lyngby Denmark Keywords crystal structure feedback inhibition gene therapy pro-drug activation Correspondence H. Eklund Department of Molecular Biology Swedish University of Agricultural Sciences Box 590 BiomedicalCenter S-751 24 Uppsala Sweden Fax 46 18 53 69 71 Tel 46 18 475 4559 E-mail hasse@ Present address AstraZeneca R D Molndal Sweden tPresent address Celland Organism Biology Lund University Sweden Received 12 April2005 revised 30 May 2005 accepted 3 June 2005 doi The Drosophila melanogaster deoxyribonucleoside kinase Dm-dNK double mutant N45D N64D was identified during a previous directed evolution study. This mutant enzyme had a decreased activity towards the natural substrates and decreased feedback inhibition with dTTP whereas the activity with 3 -modified nucleoside analogs like 3 -azidothymidine AZT was nearly unchanged. Here we identify the mutation N64D as being responsible for these changes. Furthermore we crystallized the mutant enzyme in the presence of one of its substrates thymidine and the feedback inhibitor dTTP. The introduction of the charged Asp residue appears to destabilize the LID region residues 167-176 of the enzyme by electrostatic repulsion and no hydrogen bond to the 3 -OH is made in the substrate complex by Glu172 of the LID region. This provides a binding space for more bulky 3 -substituents like the azido group in AZT but influences negatively the interactions between Dm-dNK substrates and .

• Báo cáo khoa học
• scientific reports
• Report medicine
• traditional medicine
• Crystal structure
• medical analysis
• biochemical studies
• Zizyphus mauritiana Lamk
• Biochemical constitutes
• Ber selection 1
• Studies on the pattern
• Pattern of changes biochemical constitutes
• Studies on Tikka disease
• Tikka disease
• Sowing dates
• Biochemical parameters of groundnut
• Biochemical parameters
• Studies on biochemical changes
• Biochemical changes
• Cell wall degrading enzymes
• Papaya fruit inoculated
• Colletotrichum demetium
• Vindhyan zone
• Haemato biochemical profile
• Haemato biochemical profile of goats
• Goats in Vindhyan region
• Biochemical variables
• Diaphragmatic hernia
• Various NSAIDS protocols affected
• Buffaloes treated
• Biochemical composition
• Reducing and Non reducing sugar
• Non reducing sugar
• Biochemical composition of various tomato
• Various tomato (Solanum lycopersicum L )
• environmental medicine
• Hepatobiliary disorders
• Serum biochemistry
• Hemato biochemical studies
• Hepatobiliary disorders in dogs
• Elevated total leucocyte
• Agricultural science
• Physiological and biochemical studies
• Wheat plants by application
• Amino acids and yeast extract
• Physio chemical
• Water relations
• Lucknow 49
• Ascarbic acid
• Different cultivars
• Guava under eastern
• Biochemical studies on adverse health
• Adverse health effects of arsenic
• Chromium in buffaloes
• Level of arsenic and chromium
• Heavy metals in buffaloes
• PyometraCEH complex
• Haemato biochemical evaluation
• Bitches affected
• Cystic endometrial hyperplasia pyometra complex
• Haemato biochemical studies
• Sloth bears
• HematoBiochemical changes
• Biochemical values
• Hemato biochemical changes
• Xylazine Zolazepam
• Sahiwal cows
• Blood metabolites
• Complete lactation in Sahiwal cows
• breast cancer
• medicine
• Hematopoietic
• medical knowledge