Modes of binding of guanosine monophosphates to ribonuclease T1 - A computer modelling study

Balaji, PV and Saenger, W and Rao, VSR (1991) Modes of binding of guanosine monophosphates to ribonuclease T1 - A computer modelling study. In: Current Science (Bangalore), 60 (6). pp. 363-373.

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Abstract

Computer-modelling studies on the modes of binding of the three guanosine monophosphate inhibitors 2'-GMP, 3'-GMP, and 5'-GMP to ribonuclease (RNase) T1 have been carried out by energy minimization in Cartesian-coordinate space. The inhibitory power was found to decrease in the order 2'-GMP > 3'-GMP > 5'-GMP in agreement with the experimental observations. The ribose moiety was found to form hydrogen bonds with the protein in all the enzyme-inhibitor complexes, indicating that it contributes to the binding energy and does not merely act as a spacer between the base and the phosphate moieties as suggested earlier. 2'-GMP and 5'-GMP bind to RNase T1 in either of the two ribose puckered forms (with C3'-endo more favoured over the C2'-endo) and 3'-GMP binds to RNase T1 predominantly in C3'-endo form. The catalytically important residue His-92 was found to form hydrogen bond with the phosphate moiety in all the enzyme-inhibitor complexes, indicating that this residue may serve as a general acid group during catalysis. Such an interaction was not found in either X-ray or two-dimensional NMR studies.

Item Type:	Journal Article
Publication:	Current Science (Bangalore)
Publisher:	Indian Academy of Sciences
Additional Information:	Copyright of this article belongs to Indian Academy of Sciences.
Keywords:	Molecular-Dynamics Simulations;Nucleic-Acids;Force-Field; Free Enzyme;Proteins;Complex;Solvent.
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	24 Nov 2010 08:49
Last Modified:	24 Nov 2010 08:49
URI:	http://eprints.iisc.ac.in/id/eprint/33992

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