Abstract
The nonamer r(GCUUCGGC)dBrU, where dBrU is 5-bromo-2'-deoxyuridine, contains the tetraloop sequence UUCG. It crystallizes in the presence of Rh(NH3)6Cl3. In solution the oligomer is expected to form a hairpin loop but the x-ray structure analysis, to a resolution of 1.6 A, indicates an eight-base-pair A-RNA duplex containing a central block of two G.U and two C.U pairs. Self-pairs which approximate to Watson-Crick geometry are also formed in the extended crystal structure between symmetry-related BrU residues and are part of infinite double-helical stacks. The G.U pair is a wobble base pair analogous to the G.T pair found in DNA fragments. The C.U mismatch involves one hydrogen-bonded contact between the bases and a bridging water molecule which ensures a good fit of the base pair in the RNA helix. The BrU.BrU pair is held by two hydrogen bonds in an orientation which is compatible with duplex geometry. The structure observed within the crystal has some parallels with the structure of globular RNAs, and the presence of stable, noncanonical base pairs has implications for the prediction of RNA secondary structure.
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Selected References
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- Chastain M., Tinoco I., Jr Structural elements in RNA. Prog Nucleic Acid Res Mol Biol. 1991;41:131–177. doi: 10.1016/S0079-6603(08)60008-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cornelis A. G., Haasnoot J. H., den Hartog J. F., de Rooij M., van Boom J. H., Cornelis A. Local destabilisation of a DNA double helix by a T--T wobble pair. Nature. 1979 Sep 20;281(5728):235–236. doi: 10.1038/281235a0. [DOI] [PubMed] [Google Scholar]
- Doucet J., Benoit J. P., Cruse W. B., Prange T., Kennard O. Coexistence of A- and B-form DNA in a single crystal lattice. Nature. 1989 Jan 12;337(6203):190–192. doi: 10.1038/337190a0. [DOI] [PubMed] [Google Scholar]
- Heus H. A., Pardi A. Structural features that give rise to the unusual stability of RNA hairpins containing GNRA loops. Science. 1991 Jul 12;253(5016):191–194. doi: 10.1126/science.1712983. [DOI] [PubMed] [Google Scholar]
- Holbrook S. R., Cheong C., Tinoco I., Jr, Kim S. H. Crystal structure of an RNA double helix incorporating a track of non-Watson-Crick base pairs. Nature. 1991 Oct 10;353(6344):579–581. doi: 10.1038/353579a0. [DOI] [PubMed] [Google Scholar]
- Hunter W. N., Brown T., Anand N. N., Kennard O. Structure of an adenine-cytosine base pair in DNA and its implications for mismatch repair. Nature. 1986 Apr 10;320(6062):552–555. doi: 10.1038/320552a0. [DOI] [PubMed] [Google Scholar]
- Jaeger J. A., Turner D. H., Zuker M. Improved predictions of secondary structures for RNA. Proc Natl Acad Sci U S A. 1989 Oct;86(20):7706–7710. doi: 10.1073/pnas.86.20.7706. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kennard O., Salisbury S. A. Oligonucleotide X-ray structures in the study of conformation and interactions of nucleic acids. J Biol Chem. 1993 May 25;268(15):10701–10704. [PubMed] [Google Scholar]
- Kim S. H., Suddath F. L., Quigley G. J., McPherson A., Sussman J. L., Wang A. H., Seeman N. C., Rich A. Three-dimensional tertiary structure of yeast phenylalanine transfer RNA. Science. 1974 Aug 2;185(4149):435–440. doi: 10.1126/science.185.4149.435. [DOI] [PubMed] [Google Scholar]
- Modrich P. DNA mismatch correction. Annu Rev Biochem. 1987;56:435–466. doi: 10.1146/annurev.bi.56.070187.002251. [DOI] [PubMed] [Google Scholar]
- Moras D., Comarmond M. B., Fischer J., Weiss R., Thierry J. C., Ebel J. P., Giegé R. Crystal structure of yeast tRNAAsp. Nature. 1980 Dec 25;288(5792):669–674. doi: 10.1038/288669a0. [DOI] [PubMed] [Google Scholar]
- Robertus J. D., Ladner J. E., Finch J. T., Rhodes D., Brown R. S., Clark B. F., Klug A. Structure of yeast phenylalanine tRNA at 3 A resolution. Nature. 1974 Aug 16;250(467):546–551. doi: 10.1038/250546a0. [DOI] [PubMed] [Google Scholar]
- Varani G., Cheong C., Tinoco I., Jr Structure of an unusually stable RNA hairpin. Biochemistry. 1991 Apr 2;30(13):3280–3289. doi: 10.1021/bi00227a016. [DOI] [PubMed] [Google Scholar]
- Woese C. R., Winker S., Gutell R. R. Architecture of ribosomal RNA: constraints on the sequence of "tetra-loops". Proc Natl Acad Sci U S A. 1990 Nov;87(21):8467–8471. doi: 10.1073/pnas.87.21.8467. [DOI] [PMC free article] [PubMed] [Google Scholar]