Premium
Theoretical studies on the interaction of proteins with base pairs. II. Effect of external H‐bond interactions on the stability of guanine–cytosine and non‐Watson–Crick pairs
Author(s) -
Sarai Akinori,
Saito Minoru
Publication year - 1985
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560280307
Subject(s) - molecular structure of nucleic acids: a structure for deoxyribose nucleic acid , base pair , cytosine , chemistry , guanine , dna , nucleobase , uracil , crystallography , stereochemistry , nucleotide , biochemistry , gene
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.