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1fix
From Proteopedia
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'''THE STRUCTURE OF AN RNA/DNA HYBRID: A SUBSTRATE OF THE RIBONUCLEASE ACTIVITY OF HIV-1 REVERSE TRANSCRIPTASE''' | '''THE STRUCTURE OF AN RNA/DNA HYBRID: A SUBSTRATE OF THE RIBONUCLEASE ACTIVITY OF HIV-1 REVERSE TRANSCRIPTASE''' | ||
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==About this Structure== | ==About this Structure== | ||
| - | + | Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FIX OCA]. | |
==Reference== | ==Reference== | ||
The structure of an RNA/DNA hybrid: a substrate of the ribonuclease activity of HIV-1 reverse transcriptase., Horton NC, Finzel BC, J Mol Biol. 1996 Dec 6;264(3):521-33. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8969302 8969302] | The structure of an RNA/DNA hybrid: a substrate of the ribonuclease activity of HIV-1 reverse transcriptase., Horton NC, Finzel BC, J Mol Biol. 1996 Dec 6;264(3):521-33. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8969302 8969302] | ||
| - | [[Category: Protein complex]] | ||
[[Category: Finzel, B C.]] | [[Category: Finzel, B C.]] | ||
[[Category: Horton, N C.]] | [[Category: Horton, N C.]] | ||
| - | [[Category: | + | [[Category: Double helix]] |
| - | [[Category: | + | [[Category: Hiv-1 primer binding site]] |
| - | [[Category: | + | [[Category: Right handed dna/rna hybrid]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 16:22:53 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 13:22, 2 May 2008
THE STRUCTURE OF AN RNA/DNA HYBRID: A SUBSTRATE OF THE RIBONUCLEASE ACTIVITY OF HIV-1 REVERSE TRANSCRIPTASE
Overview
The structure of a complementary hybrid duplex of RNA and DNA has been determined by X-ray crystallography. A ten residue DNA oligonucleotide of sequence 5'-G-G-C-G-C-C-C-G-A-A-3' was annealed to complementary RNA (5'-u-u-c-g-g-g-c-g-c-c-3') and crystallized, producing tetragonal crystals that diffract to 2.3 A resolution. The hybrid adopts a geometry that is neither strictly A nor B-form, rather the helix possesses qualities of both, reminiscent of spectroscopic descriptions of a hybrid conformation, or H-form. All of the ribonucleotides maintain the C3'-endo conformation seen in A-form, while both C3'-endo and C2'-endo conformations are found in the deoxyribonucleotides. The minor groove width (8.5 to 10.5 A) is intermediate between standard values for A (11 A) and B-form (7.4 A) DNA. The global parameters rise and base-pairs tilt (or inclination) are like that of A-DNA, however the slide and x displacement (Dx) are more like that of A-RNA, thus giving the hybrid a unique conformation. In addition, the 10-mer crystallizes in a manner that allows the formation of dimers that stack end-to-end, thereby providing a glimpse of how an extended (20 base-pair) helix of RNA-DNA hybrid might appear. This duplex sequence was selected for study because it is specifically recognized by the ribonuclease H function of HIV reverse transcriptase. A structure of a substrate of this enzyme is of potential value in understanding requirements for the selectivity of this important drug target. The minor groove of the hybrid duplex, lined with the 2-OH of the ribose rings, is the single distinguishing characteristic of the RNA/DNA hybrid, undoubtedly an important structural feature conferring selectivity.
About this Structure
Full crystallographic information is available from OCA.
Reference
The structure of an RNA/DNA hybrid: a substrate of the ribonuclease activity of HIV-1 reverse transcriptase., Horton NC, Finzel BC, J Mol Biol. 1996 Dec 6;264(3):521-33. PMID:8969302 Page seeded by OCA on Fri May 2 16:22:53 2008
