caa a22 4500 378853171 CHVBK 20180305123328.0 cr unu---uuuuu 161128e20030820xx s 000 0 eng 10.1515/BC.2003.130 doi (NATIONALLICENCE)gruyter-10.1515/BC.2003.130 Determination of the NMR Structure of Gln25-Ribonuclease T1 [Elektronische Daten] [K.-i. Hatano, M. Kojima, E.-i. Suzuki, M. Tanokura, K. Takahashi] Ribonuclease (RNase) T1 is a guanyloribonuclease, having two isozymes in nature, Gln25- and Lys25- RNase T1. Between these two isozymes, there is no difference in catalytic activity and threedimensional structure; however, Lys25-RNase T1 is slightly more stable than Gln25-RNase T1. Recently, it has been suggested that the existence of a salt bridge between Lys25 and Asp29/Glu31 in Lys25-RNase T1 contributes to the stability. To elucidate the effects of the replacement of Lys25 with a Gln on the conformation and microenvironments of RNase T1 in detail, the three-dimensional solution structure of Gln25-RNase T1 was determined by simulated-annealing calculations. As a result, the topology of the overall folding was shown to be very similar to that of the Lys25-isozyme except for some differences. In particular, there were two differences in the property of torsion angles of the two disulfide bonds and the conformations of the residues 11-13, 63-66, and 92-93. With regard to the residues 11-13, the lack of the abovementioned salt bridge in Gln25-RNase T1 was thought to induce the conformational difference of this segment as compared with the Lys25-isozyme. Furthermore, it was proposed that the perturbation of this segment might transfer to the residues 92-93 via the two disulfide bonds. Copyright © 2003 by Walter de Gruyter GmbH & Co. KG Biochemistry nationallicence Molecular biology nationallicence Cellular biology nationallicence Hatano K.-i aut Kojima M. aut Suzuki E.-i aut Tanokura M. aut Takahashi K. aut Biological Chemistry Walter de Gruyter 384/8(2003-08-20), 1173-1183 1431-6730 384:8<1173 2003 384 bchm https://doi.org/10.1515/BC.2003.130 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/BC.2003.130 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hatano K.-i aut NATIONALLICENCE 700 1- Kojima M. aut NATIONALLICENCE 700 1- Suzuki E.-i aut NATIONALLICENCE 700 1- Tanokura M. aut NATIONALLICENCE 700 1- Takahashi K. aut NATIONALLICENCE 773 0- Biological Chemistry Walter de Gruyter 384/8(2003-08-20), 1173-1183 1431-6730 384:8<1173 2003 384 bchm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter