Nowakowski J, Shim P J, Prasad G S, Stout C D, Joyce G F
Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
Nat Struct Biol. 1999 Feb;6(2):151-6. doi: 10.1038/5839.
The structure of a large nucleic acid complex formed by the 10-23 DNA enzyme bound to an RNA substrate was determined by X-ray diffraction at 3.0 A resolution. The 82-nucleotide complex contains two strands of DNA and two strands of RNA that form five double-helical domains. The spatial arrangement of these helices is maintained by two four-way junctions that exhibit extensive base-stacking interactions and sharp turns of the phosphodiester backbone stabilized by metal ions coordinated to nucleotides at these junctions. Although it is unlikely that the structure corresponds to the catalytically active conformation of the enzyme, it represents a novel nucleic acid fold with implications for the Holliday junction structure.
通过3.0埃分辨率的X射线衍射确定了由与RNA底物结合的10 - 23 DNA酶形成的大型核酸复合物的结构。这个82个核苷酸的复合物包含两条DNA链和两条RNA链，它们形成了五个双螺旋结构域。这些螺旋的空间排列由两个四向连接点维持，这两个连接点表现出广泛的碱基堆积相互作用，并且磷酸二酯主链的急转弯由与这些连接点处核苷酸配位的金属离子稳定。尽管该结构不太可能对应于酶的催化活性构象，但它代表了一种对霍利迪连接体结构有启示意义的新型核酸折叠形式。
