307d

<StructureSection load='307d' size='340' side='right' caption='[[307d]], [[Resolution|resolution]] 1.85&Aring;' scene=''>

<table><tr><td colspan='2'>[[307d]] is a 6 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=307D OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=307D FirstGlance]. <br>

</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=307d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=307d OCA], [http://pdbe.org/307d PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=307d RCSB], [http://www.ebi.ac.uk/pdbsum/307d PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=307d ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

The non-self-complementary DNA decamer C-A-A-A-G-A-A-A-A-G/C-T-T-T-T-C-T-T-T-G is a DNA/DNA analogue of a portion of the polypurine tract or PPT, which is a RNA/DNA hybrid that serves as a primer for synthesis of the (+) DNA strand by HIV reverse transcriptase (RT), and which is not digested by the RNase H domain of reverse transcriptase following (-) strand synthesis. The same unusual conformation that eludes RNase H, thought to be a change in width of minor groove, may also be responsible for the inhibition of HIV RT by minor groove binding drugs such as distamycin and their bis-linked derivatives. The present X-ray crystal structure of this DNA decamer exhibits the usual properties of A-tract B-DNA under biologically relevant conditions: large propeller twist of base-pairs, narrowed minor groove, and a straight helix axis. Groove narrowing is fully developed in the A-A-A-A region, but not in the A-A-A region, which previous investigators have proposed as being too short to exhibit typical A-tract properties. The RNA/DNA hybrid produced by HIV reverse transcriptase during (-) strand synthesis presumably forms a "heteromerous" or H-helix with narrower minor groove than an A-helical RNA/RNA duplex. If the narrowing of minor groove in A-tract H-helices is comparable to that seen in A-tract B-helices, then the narrowed minor groove of the polypurine tract could make the second primer site both (1) impervious to RNase H digestion, and (2) susceptible to inhibition by minor groove binding drugs.

Structure of a DNA analog of the primer for HIV-1 RT second strand synthesis.,Han GW, Kopka ML, Cascio D, Grzeskowiak K, Dickerson RE J Mol Biol. 1997 Jun 27;269(5):811-26. PMID:9223643<ref>PMID:9223643</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 307d" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Cascio, D]]

[[Category: Dickerson, R E]]

[[Category: Grzeskowiak, K]]

[[Category: Han, G W]]

[[Category: Kopka, M L]]

[[Category: Double helix]]