165d
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THE STRUCTURE OF A MISPAIRED RNA DOUBLE HELIX AT 1.6 ANGSTROMS RESOLUTION AND IMPLICATIONS FOR THE PREDICTION OF RNA SECONDARY STRUCTURE
OverviewOverview
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.
About this StructureAbout this Structure
165D is a Protein complex structure of sequences from [1] with RHD as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Structure of a mispaired RNA double helix at 1.6-A resolution and implications for the prediction of RNA secondary structure., Cruse WB, Saludjian P, Biala E, Strazewski P, Prange T, Kennard O, Proc Natl Acad Sci U S A. 1994 May 10;91(10):4160-4. PMID:7514296
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