ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
We studied the stability of guanine-cytosine and non-Watson-Crick pairs in the presence of H-bond interactions with various amino acid side chains, by using ab initio MO method. The external H-bond interactions stabilize or destabilize the base pairs, depending on the type of interacting residues and the site of the interaction. The pattern of the H-bond effect on the base-pair stability is quite different than in the case of adenine-uracil pair previously reported. From the present results, together with the previous results on adenine-uracil pair, we obtain a general rule for the effect of external H-bond interactions on the stability of base pairs. The site-specific effect of the H-bond interactions can be consistently explained by the cooperative interaction between external and base-pair H bonds. We discuss the application of the present results in the following biological processes: One is the protein-induced specific melting of double-stranded DNA, which is involved in transcription process. The present results suggest that H-bond interactions of protein residues at specific site of base pairs can weaken base-pair H bonding, which would assist the opening of double-stranded DNA. The other is the control of mutation in replication process. We suggest that proteins can discriminate non-Watson-Crick pairs against Watson-Crick pairs by H-bond interactions and can either induce or suppress mutation during DNA replication.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560280307
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