THE ROLE OF BACKBONE OXYGEN-ATOMS IN THE ORGANIZATION OF NUCLEIC-ACIDTERTIARY STRUCTURE - ZIPPERS, NETWORKS, CLAMPS, AND C-H-CENTER-DOT-CENTER-DOT-CENTER-DOT-O HYDROGEN-BONDS

Authors
Citation
I. Berger et M. Egli, THE ROLE OF BACKBONE OXYGEN-ATOMS IN THE ORGANIZATION OF NUCLEIC-ACIDTERTIARY STRUCTURE - ZIPPERS, NETWORKS, CLAMPS, AND C-H-CENTER-DOT-CENTER-DOT-CENTER-DOT-O HYDROGEN-BONDS, Chemistry, 3(9), 1997, pp. 1400-1404
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry
Journal title
Chemistry → ACNP
ISSN journal
0947-6539
Volume
3
Issue
9
Year of publication
1997
Pages
1400 - 1404
Database
ISI
SICI code
0947-6539(1997)3:9<1400:TROBOI>2.0.ZU;2-T
Abstract
Tight packing between structural elements is a prerequisite for molecu lar recognition and catalysis. In proteins, alpha-helices and beta-she ets present the amino acid side chains on the surface while the polar amide bonds are buried. The opposite is found in double-and polystrand ed nucleic acids, where negatively charged phosphates occupy the surfa ce and the side chains are hydrogen bonded in the core. Thus the quest ion arises: How do densely packed nucleic acid molecules achieve close approach, despite the repulsion between phosphates that would appear to preclude tight contacts? One obvious answer is by mediating interst rand contacts through coordinated cations that can screen the negative charges. In this contribution, however, we highlight a variety of alt ernative direct interactions involving atoms of the sugar-phosphate ba ckbone that can promote tight packing of RNA and DNA into functional m olecules. We have analyzed the existing nucleic acid crystal structure s in terms of the presence of close contacts between backbone regions. In RNA, ribose 2'-hydroxyl groups were observed to mediate such conta cts in the majority of cases. However, their absence in DNA does not p revent oligodeoxynucleotides from packing tightly, aided by various in teractions between backbone atoms.