Author:

Keywords:

Crystallography, X-Ray, Models, Molecular, Nuclear Magnetic Resonance, Biomolecular, Nucleic Acid Conformation, Nucleic Acid Heteroduplexes, Nucleosides, RNA, Solutions, Sugar Alcohols, Thermodynamics, Water, Science & Technology, Physical Sciences, Chemistry, Multidisciplinary, Chemistry, NUCLEIC-ACID STRUCTURE, DEPENDENT DNA-STRUCTURE, CHEMICAL ETIOLOGY, X-RAY, RNA/DNA HYBRID, OLIGONUCLEOTIDES, SUBSTRATE, 03 Chemical Sciences, General Chemistry, 34 Chemical sciences, 40 Engineering

Abstract:

The crystal structure of a decameric HNA/RNA (HNA = 2',3'-dideoxy-1',5'-anhydro-d-arabinohexitol nucleic acid) hybrid with the RNA sequence 5'-GGCAUUACGG-3' is the first crystal structure of a hybrid duplex between a naturally occurring nucleic acid and a strand, which is fully modified to contain a six-membered ring instead of ribose. The presence of four duplex helices in the asymmetric unit allows for a detailed discussion of hydration, which revealed a tighter spinelike backbone hydration for the HNA- than for the RNA-strands. The reinforced backbone hydration is suggested to contribute significantly to the exceptional stability of HNA-containing duplexes and might be one of the causes for the evolutionary preference for ribose-derived nucleic acids.