1mwg: Difference between revisions

[[Image:1mwg.jpg|left|200px]]<br /><applet load="1mwg" size="350" color="white" frame="true" align="right" spinBox="true"  

The three-dimensional solution structure of the RNA self-complementary duplex [sequence: see text] was derived from two-dimensional NMR and the iterative relaxation matrix approach. Each GA mismatch forms two hydrogen bonds: A-NH6 to G-O6 and A-N1 to G-NH1 (imino). This is the first three-dimensional RNA structure with imino hydrogen-bonded tandem GA mismatches. This GA structure is totally different from the sheared tandem GA structure in [sequence: see text] which also has two hydrogen bonds: A-N7 to G-NH2 and A-NH6 to G-N3 [SantaLucia, J., Jr., &amp; Turner, D. H. (1993) Biochemistry 32, 12612-12623]. In particular, the sheared and imino GA mismatches produce a narrowing and widening of the backbone, respectively. The results show that substitutions of Watson-Crick base pairs can have dramatic effects on the three-dimensional structures of adjacent non-Watson-Crick paired regions; i.e., the structure depends on sequence context. Thus compensating substitutions in site-directed mutagenesis experiments may not always restore biological activities.

1MWG is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MWG OCA].  

[[Category: Turner, D H.]]

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