Morcock D R, Sowder R C, Casas-Finet J R
AIDS Vaccine Program, SAIC Frederick, National Cancer Institute-Frederick Cancer Research and Development Center, Building 535-4, P.O. Box B, Frederick, MD 21702, USA.
FEBS Lett. 2000 Jul 7;476(3):190-3. doi: 10.1016/s0014-5793(00)01723-3.
Zinc finger (ZF) domains in retroviral nucleocapsid proteins usually contain one histidine per metal ion coordination complex (Cys-X(2)-Cys-X(4)-His-X(4)-Cys). Visna virus nucleocapsid protein, p8, has two additional histidines (in the second of its two ZFs) that could potentially bind metal ions. Absorption spectra of cobalt-bound ZF2 peptides were altered by Cys alkylation and mutation, but not by mutation of the extra histidines. Our results show that visna p8 ZFs involve three Cys and one His in the canonical spacing in metal ion coordination, and that the two additional histidines appear to interact with nucleic acid bases in p8-DNA complexes.
逆转录病毒核衣壳蛋白中的锌指（ZF）结构域通常每个金属离子配位复合物含有一个组氨酸（半胱氨酸-X(2)-半胱氨酸-X(4)-组氨酸-X(4)-半胱氨酸）。维斯纳病毒核衣壳蛋白p8在其两个锌指结构的第二个结构中有另外两个组氨酸，它们可能潜在地结合金属离子。钴结合的ZF2肽的吸收光谱因半胱氨酸烷基化和突变而改变，但不受额外组氨酸突变的影响。我们的结果表明，维斯纳p8锌指结构在金属离子配位的典型间距中涉及三个半胱氨酸和一个组氨酸，并且这两个额外的组氨酸似乎与p8-DNA复合物中的核酸碱基相互作用。
