Summary information and primary citation
- PDB-id
-
126d;
SNAP-derived features in text and
JSON formats
- Class
- DNA
- Method
- X-ray (2.0 Å)
- Summary
- Crystal structure of catggccatg and its implications
for a-tract bending models
- Reference
-
Goodsell DS, Kopka ML, Cascio D, Dickerson RE (1993):
"Crystal
structure of CATGGCCATG and its implications for A-tract
bending models." Proc.Natl.Acad.Sci.USA,
90, 2930-2934. doi: 10.1073/pnas.90.7.2930.
- Abstract
- 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.
