Crystallographic studies of metal ion - DNA interactions: Different binding modes of cobalt(II), copper(II) and barium(II) to nof guanines in Z-DNA and a drug-DNA complex

Yi gui Gao, M. Sriram, Andrew H.J. Wang

研究成果: 雜誌貢獻文章同行評審

124 引文 斯高帕斯(Scopus)

摘要

Metal ion coordination to nucleic acids is not only required for charge neutralization, it is also essential for the biological function of nucleic acids. The structural impact of different metal ion coordinations on DNA helices is an open question. We carried out X-ray diffraction analyses of the interactions of the two transition metal Ions Co(ll) and Cu(ll) and an alkaline earth metal Ion Ba(ll), with DNA of different conformations. In crystals, Co(ll) Ion binds exclusively at the N7 position of guanine bases by direct coordination. The coordination geometry around Co(ll) is octahedral, although some sites have an incomplete hydration shell. The averaged Co-N7 bond distance is 2.3.A. The averaged Co-N7-C8 angle Is 121°, significantly smaller than the value of 128° If the Cc/N7 vector were to bisect the C5-N7-C8 bond angle. Model building of Co(ll) binding to guanine N7 In B/DNA indicates that the coordinated waters in the axial positions would have a van der Waals clash with the neighboring base on the 5' side. In contrast, the major groove of A-DNA does not have enough room to accommodate the entire hydration shell. This suggests that Co(ll) binding to either B-DNA or A-DNA may induce significant conformational changes. The Z-DNA structure of Cu(ll)-soaked CGCGTG crystal revealed that the Cu(ll) Ion is bis-coordinated to N7 position of G10 and 'G12 (denotes a symmetry-related position) bases with a trigonal blpyramld geometry, suggesting a possible N7-Cu-N7 crosslinking mechanism. A similar bis-coordination to two guanines has also been seen in the interaction of Ba(ll) in m'CGUAmSCG Z-DNA crystal and of Ba(ll) with two other Z-DNA crystals.

原文英語
頁(從 - 到)4093-4101
頁數9
期刊Nucleic Acids Research
21
發行號17
DOIs
出版狀態已發佈 - 8月 25 1993
對外發佈

ASJC Scopus subject areas

  • 遺傳學

指紋

深入研究「Crystallographic studies of metal ion - DNA interactions: Different binding modes of cobalt(II), copper(II) and barium(II) to nof guanines in Z-DNA and a drug-DNA complex」主題。共同形成了獨特的指紋。

引用此