126d

[[Image:126d.gif|left|200px]]<br /><applet load="126d" size="450" color="white" frame="true" align="right" spinBox="true"

caption="126d, resolution 2.000&Aring;" />

'''CRYSTAL STRUCTURE OF CATGGCCATG AND ITS IMPLICATIONS FOR A-TRACT BENDING MODELS'''<br />

==Overview==

The single-crystal x-ray analysis of orthorhombic CATGGCCATG has revealed, a previously unrecognized mode of intrinsic bending in DNA. The decamer, shows a smooth bend of 23 degrees over the central four base pairs, caused, by preferential stacking interactions at guanine bases. The bend is, produced by a roll of base pairs along their long axes, in a direction, that compresses the wide major groove of the double helix. This, major-groove-compressing bend at GGC, plus the abundant crystallographic, evidence that runs of successive adenine bases (A-tracts) are straight and, unbent, requires rethinking of the models most commonly invoked to explain, A-tract bending. A decade of excellent experimental work involving gel, migration experiments, cyclization kinetics, and nucleosome phasing has, clearly established that introduction of short A-tracts into a general DNA, sequence in synchrony with the natural repeat of the helix leads to, bending. But it does not logically and inevitably follow that the actual, bending is to be found within these introduced A-tracts or even at, junctions with general-sequence B-DNA.

 

==About this Structure==

126D 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://ispc.weizmann.ac.il/oca-bin/ocashort?id=126D OCA].

 

==Reference==

Crystal structure of CATGGCCATG and its implications for A-tract bending models., Goodsell DS, Kopka ML, Cascio D, Dickerson RE, Proc Natl Acad Sci U S A. 1993 Apr 1;90(7):2930-4. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8464909 8464909]

[[Category: Protein complex]]

[[Category: Cascio, D.]]

[[Category: Dickerson, R.E.]]

[[Category: Goodsell, D.S.]]

[[Category: Kopka, M.L.]]

[[Category: b-dna]]

[[Category: double helix]]

 

''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Sat Nov 24 21:49:38 2007''