Guanine specific binding at a DNA junction formed by d[CG(5-BrU)ACG]2 with a topoisomerase poison in the presence of Co2+Ions†,‡

The structure of the duplex d[CG(5-BrU)ACG]2 bound to 9-bromophenazine-4-carboxamide has been solved through MAD phasing at 2.0 Å resolution. It shows an unexpected and previously unreported intercalation cavity stabilized by the drug and novel binding modes of Co2+ ions at certain guanine N7 sites. For the intercalation cavity the terminal cytosine is rotated to pair with the guanine of a symmetry-related duplex to create a pseudo-Holliday junction geometry, with two such cavities linked through the minor groove interactions of the N2/N3 guanine sites at an angle of 40°, creating a quadruplex-like structure. The mode of binding of the drug is shown to be disordered, with the major conformations showing the side chain bound to the N7 position of adjacent guanines. The other end of the duplex exhibits a terminal base fraying in the presence of Co2+ ions linking symmetry-related guanines, causing the helices to intertwine through the minor groove. The stabilization of the structure by the intercalating drug shows that this class of compound may bind to DNA junctions as well as duplex DNA or to strand-nicked DNA (‘hemi-intercalated'), as in the cleavable complex. This suggests a structural basis for the dual poisoning of topoisomerase I and II enzymes by this family of drugs.

HB D Los Angeles in a Brazilian family

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Knox-Wise Family Papers - Accession 591

The Knox-Wise Family Papers includes a land grant issued to John Knox in 1768; diaries written by Dr. John Knox [1792-1859] covering the 1840s and 1850s; James N. Knox [1806-1880] covering 1859-1880; and William D. Knox [1847-1928] covering 1869-1928; indentures, deeds, receipts, court summonses and other papers of Hugh Knox [1757-1821], sheriff and justice of the peace in Chester County, South Carolina (ca. 1780s and 1790s); correspondence of James N. Knox, correspondence, and other professional papers of Dr. John Knox; correspondence, and other papers of William D. Knox, Superintendent of Education in Chester County from 1896-1928. Papers of various other members of the Knox and Wise families including Hugh Boyd Knox [1814-1886], Robert Knox [1796-1879], Sally Knox Wallace [1803-1901], Alexander Walker Wise, and Emmie R. Knox [1885-1969]; family histories of the Knox, Wise, Dunlap, Gaston, and Wilks families; church histories, photographs, and newspaper clippings. Also included are three published volumes of the United Confederate Veterans Minutes of the 21st (1911) and 25th (1915) Annual Meeting and Reunion; and the minutes of the annual reunion of the South Carolina Division of the United Confederate Veterans (1921-1927).

William Crotch, This Celebrated Child who discover'd extraordinary Talents for Music during the Third Year of his Age, was born at Norwich July 5th. 1775.

Signatur des Originals: S 36/G03990