The Reaction Mechanism and Subsites of RNase T_2 family

Research Project

Project/Area Number	08680663
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Structural biochemistry
Research Institution	Showa University
Principal Investigator	NAKAMURA Kazuo Showa University, school of Pharmaceutical sciences, Professor, 薬学部, 教授 (00012675)
Project Period (FY)	1996 – 1997
Project Status	Completed (Fiscal Year 1997)
Budget Amount *help	¥2,400,000 (Direct Cost: ¥2,400,000) Fiscal Year 1997: ¥1,000,000 (Direct Cost: ¥1,000,000) Fiscal Year 1996: ¥1,400,000 (Direct Cost: ¥1,400,000)
Keywords	Ribonuclease / X-ray analysis / Enzyme-substrate complex / X線構造解析 / 基質複合体 / サブサイト
Research Abstract	During the present study we have successfully determined the two crucial crystal structures of RNase RNAP-Rh, i.e., RNase RNAP-Rh+d (ApG) complex and RNAP-Rh (Y57W) +d (ApC) complex. Diffraction data of the crystals were collected using an oscillation camera (R-AXISIIc manufactured by Rigaku). The crystal structures were determined based on the atomic coordinates of RNase Rh, and refined using the program X-PLOR.The refinements were done successfully, and the R-values of both complexes were coverged to under 0.20. (1) we found out that there are two hydrogen-bonds between the adenine base and the enzyme, and three ones between the phosphate group and the enzyme. (2) We also found out that the subsite B2 consists of Gln32, Pro92, Ser93, Asn94, Gln95 and Phe101.