1cvy
From Proteopedia
CRYSTAL STRUCTURE OF POLYAMIDE DIMER (IMPYPYPYBETADP)2 BOUND TO CCAGATCTGG
Overview
Synthetic polyamides composed of three types of aromatic amino acids, N-methylimidazole (Im), N-methylpyrrole (Py) and N-methyl-3-hydroxypyrrole (Hp) bind specific DNA sequences as antiparallel dimers in the minor groove. The side-by-side pairings of aromatic rings in the dimer afford a general recognition code that allows all four base-pairs to be distinguished. To examine the structural consequences of changing the DNA sequence context on T.A recognition by Hp/Py pairs in the minor groove, crystal structures of polyamide dimers (ImPyHpPy)(2) and the pyrrole counterpart (ImPyPyPy)(2) bound to the six base-pair target site 5'-AGATCT-3' in a ten base-pair oligonucleotide have been determined to a resolution of 2.27 and 2.15 A, respectively. The structures demonstrate that the principles of Hp/Py recognition of T.A are consistent between different sequence contexts. However, a general structural explanation for the non-additive reduction in binding affinity due to introduction of the hydroxyl group is less clear. Comparison with other polyamide-DNA cocrystal structures reveals structural themes and differences that may relate to sequence preference.
About this Structure
Full crystallographic information is available from OCA.
Reference
Structural effects of DNA sequence on T.A recognition by hydroxypyrrole/pyrrole pairs in the minor groove., Kielkopf CL, Bremer RE, White S, Szewczyk JW, Turner JM, Baird EE, Dervan PB, Rees DC, J Mol Biol. 2000 Jan 21;295(3):557-67. PMID:10623546 Page seeded by OCA on Fri May 2 13:10:07 2008
