TAILIEUCHUNG - Báo cáo khoa học: Destabilization of psychrotrophic RNase HI in a localized fashion as revealed by mutational and X-ray crystallographic analyses

The Arg97fiGly and Asp136fiHis mutations stabilized So-RNase HI from the psychrotrophic bacterium Shewanella oneidensis MR-1 by and C, respectively, inTm, and and kJÆmol )1 , respectively, in DG(H2O). These mutations also stabilized the So-RNase HI derivative (4·-RNase HI) with quadruple thermostabilizing mutations in an additive manner. | Destabilization of psychrotrophic RNase HI in a localized fashion as revealed by mutational and X-ray crystallographic analyses Muhammad S. Rohman1 Takashi Tadokoro1 Clement Angkawidjaja1 Yumi Abe1 Hiroyoshi Matsumura2 3 Yuichi Koga1 Kazufumi Takano1 3 and Shigenori Kanaya1 1 Department of Materialand Life Science Graduate Schoolof Engineering Osaka University Japan 2 Department of Applied Chemistry Graduate Schoolof Engineering Osaka University Japan 3 CREST JST Osaka Japan Keywords crystal structure destabilization mechanism RNase HI Shewanella oneidensis MR-1 thermostabilizing mutations Correspondence S. Kanaya Department of Materialand Life Science Graduate School of Engineering Osaka University 2-1 Yamadaoka Suita Osaka 565-0871 Japan Fax 81 6 6879 7938 Tel 81 6 6879 7938 E-mail kanaya@ Received 26 September 2008 revised 11 November 2008 accepted 19 November 2008 doi The Arg97 fi Gly and Asp136 fi His mutations stabilized So-RNase HI from the psychrotrophic bacterium Shewanella oneidensis MR-1 by and C respectively in Tm and and kJ-mol-1 respectively in DG H2O . These mutations also stabilized the So-RNase HI derivative 4x-RNase HI with quadruple thermostabilizing mutations in an additive manner. As a result the resultant sextuple mutant protein 6x-RNase HI was more stable than the wild-type protein by C in Tm and kJ-mol-1 in DG H2O . To analyse the effects of the mutations on the protein structure the crystal structure of the 6x-RNase HI protein was determined at A resolution. The main chain fold and interactions of the side-chains of the 6x-RNase HI protein were basically identical to those of the wild-type protein except for the mutation sites. These results indicate that all six mutations independently affect the protein structure and are consistent with the fact that the thermostabilizing effects of the mutations are roughly additive. The introduction of favourable .

• Báo cáo khoa học
• medical reports
• thesis report
• traditional medicine
• breast cancer
• biological activities
• gastric cancer
• statements and documents scientific reports
• medical knowledge
• medical research
• clinical trials
• medical management
• health care
• medical transfer
• the developing countries