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Protonation‐induced conformational flipping in hypermodified nucleic acid base N 6 −( N −glycylcarbonyl) adenine
Author(s) -
Tewari Ravindra
Publication year - 1994
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.560510206
Subject(s) - protonation , intramolecular force , chemistry , hydrogen bond , substituent , nucleic acid , stereochemistry , base pair , crystallography , molecule , dna , biochemistry , organic chemistry , ion
The influence of accepting the hydrogen bond by N(3) of adenine on the conformational preferences of the N(6) substituent in modified nucleic acid base N 6 −( N −glycylcarbonyl)adenine (gc 6 Ade) has been modeled by the protonation of N(3). The preferred orientation of the glycylcarbonyl substituent changes on the protonation of N(3). The preferred conformation for the N(3) protonated base is the planar, intramolecular bifurcated hydrogen‐bonded structure involving the interaction of the ureido N(11)H with the N(1) of the purine and the O(13b) of the amino acid carboxyl. Another conformation of nearly equal stability, having the internal hydrogen bonding of O(13b) with the N(6)H, is also predicted. Such protonation or hydrogen‐bonding‐induced conformational flipping may enable the structural reorientation of the anticodon loop required for the functioning of tRNA. © 1994 John Wiley & Sons, Inc.