1d16: Difference between revisions
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[[ | ==STRUCTURE OF A T4 HAIRPIN LOOP ON A Z-DNA STEM AND COMPARISON WITH A-RNA AND B-DNA LOOPS== | ||
<StructureSection load='1d16' size='340' side='right' caption='[[1d16]], [[Resolution|resolution]] 2.10Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1d16]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D16 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1D16 FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1d16 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1d16 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1d16 RCSB], [http://www.ebi.ac.uk/pdbsum/1d16 PDBsum]</span></td></tr> | |||
<table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The synthetic DNA oligomer C-G-C-G-C-G-T-T-T-T-C-G-C-G-C-G crystallizes as a Z-DNA hexamer, capped at one end by a T4 loop. The crystals are monoclinic, space group C2, with a = 57.18 A, b = 21.63 A, c = 36.40 A, beta = 95.22 degrees, and one hairpin molecule per asymmetric unit. The structure of the z-hexamer stem was determined by molecular replacement, and the T4 loop was positioned by difference map methods. The final R factor at 2.1 A resolution for hairpin plus 70 water molecules is 20% for 2 sigma data, with a root-mean-square error of 0.26 A. The (C-G)3 stem resembles the free Z-DNA hexamer with minor crystal packing effects. The T4 loop differs from that observed on a B-DNA stem in solution, or in longer loops in tRNA, in that it shows intraloop and intermolecular interactions rather than base stacking on the final base-pair of the stem. Bases T7, T8 and T9 stack with one another and with the sugar of T7. Two T10 bases from different molecules stack between the C1-G12 terminal base-pairs of a third and fourth molecule, to simulate a T.T "base-pair". Distances between thymine N and O atoms suggest that the two thymine bases are hydrogen bonded, and a keto-enol tautomer pair is favored over disordered keto-keto wobble pairs. The hairpin molecules pack in the crystal in herringbone columns in a manner that accounts well for the observed relative crystal growth rates in a, b and c directions. Hydration seems to be most extensive around the phosphate groups, with lesser hydration within the grooves. | |||
Structure of a T4 hairpin loop on a Z-DNA stem and comparison with A-RNA and B-DNA loops.,Chattopadhyaya R, Grzeskowiak K, Dickerson RE J Mol Biol. 1990 Jan 5;211(1):189-210. PMID:2299669<ref>PMID:2299669</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
== | __TOC__ | ||
</StructureSection> | |||
[[Category: Chattopadhyaya, R.]] | [[Category: Chattopadhyaya, R.]] | ||
[[Category: Dickerson, R E.]] | [[Category: Dickerson, R E.]] |