title: Crystal structure of the DNA decamer d(CGCAATTGCG) complexed with the minor groove binding drug netropsin.
abstract: The crystal structure of netropsin bound to the decamer d(CGCAATTGCG) has been determined at 2.4 A resolution. This is the first example of a crystal structure of netropsin bound to decamer DNA. The central eight bases of each DNA single-strand base pair with a self-complementary strand to form an octamer B-DNA duplex. These duplexes lie end to end within the unit cell. The terminal 5'-C and G-3' bases are unpaired and interact with the neighboring duplexes via interactions within both the major and minor groove to form base triplet interactions of the type C(+)-G x C and G*(G x C), respectively. The triplet interaction of the type C(+)-G x C is known to exist within triplex DNA with the C+ base oriented parallel with the Watson-Crick guanine base to which it hydrogen bonds. The netropsin molecule lies within the minor groove of the octamer duplex and assumes a class I type position, with bifurcated hydrogen-bonding interactions from the amide groups of the netropsin to the A x T base pairs of the minor groove. The netropsin molecule fits within a five base pair long minor groove site by bending of the flexible amidinium group at one end of the drug.
authors.affiliation: The CRC Biomolecular Structure Unit, The Institute of Cancer Research, Sutton, Surrey, U.K. c.nunn@icr.ac.uk
authors.forename: C M
authors.initials: CM
authors.lastname: Nunn
authors.forename: E
authors.initials: E
authors.lastname: Garman
authors.forename: S
authors.initials: S
authors.lastname: Neidle
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D009429:Netropsin / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D012984:Software
chemical_list: D000900:Anti-Bacterial Agents; D009429:Netropsin; D004247:DNA