Structure of an RNA internal loop consisting of tandem C-A+ base pairs. Biochemistry 1998 Aug 25;37(34):11726-31
Date
08/26/1998Pubmed ID
9718295DOI
10.1021/bi980758jScopus ID
2-s2.0-0001475194 (requires institutional sign-in at Scopus site) 65 CitationsAbstract
The crystal structure of the RNA octamer 5'-CGC(CA)GCG-3' has been determined from X-ray diffraction data to 2.3 A resolution. In the crystal, this oligomer forms a self-complementary double helix in the asymmetric unit. Tandem non-Watson-Crick C-A and A-C base pairs comprise an internal loop in the middle of the duplex, which is incorporated with little distortion of the A-form double helix. From the geometry of the C-A base pairs, it is inferred that the adenosine imino group is protonated and donates a hydrogen bond to the carbonyl group of the cytosine. The wobble geometry of the C-A+ base pairs is very similar to that of the common U-G non-Watson-Crick pair.
Author List
Jang SB, Hung LW, Chi YI, Holbrook EL, Carter RJ, Holbrook SRAuthor
Young-In Chi PhD Assistant Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdenineBase Composition
Crystallography, X-Ray
Cytosine
Hydrogen Bonding
Models, Molecular
Nucleic Acid Conformation
Oligoribonucleotides
RNA
Thermodynamics
