Berkovits-Cymet Holly J, Amann Barbara T, Berg Jeremy M
Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Biochemistry. 2004 Feb 3;43(4):898-903. doi: 10.1021/bi035159d.
The structure of a CCHHC zinc-binding domain from neural zinc finger factor-1 (NZF-1) has been determined in solution though the use of NMR methods. This domain is a member of a family of domains that have the Cys-X(4)-Cys-X(4)-His-X(7)-His-X(5)-Cys consensus sequence. The structure determination reveals a novel fold based around a zinc(II) ion coordinated to three Cys residues and the second of the two conserved His residues. The other His residue is stacked between the metal-coordinated His residue and a relatively conserved aromatic residue. Analysis of His to Gln sequence variants reveals that both His residues are required for the formation of a well-defined structure, but neither is required for high-affinity metal binding at a tetrahedral site. The structure suggests that a two-domain protein fragment and a double-stranded DNA binding site may interact with a common two-fold axis relating the two domains and the two half-sites of the DNA-inverted repeat.
通过核磁共振方法，已在溶液中确定了来自神经锌指因子-1（NZF-1）的CCHHC锌结合结构域的结构。该结构域是具有Cys-X(4)-Cys-X(4)-His-X(7)-His-X(5)-Cys共有序列的结构域家族的成员。结构测定揭示了一种基于锌（II）离子的新折叠，该锌离子与三个半胱氨酸残基和两个保守组氨酸残基中的第二个配位。另一个组氨酸残基堆积在金属配位的组氨酸残基和一个相对保守的芳香族残基之间。对组氨酸到谷氨酰胺序列变体的分析表明，两个组氨酸残基对于形成明确的结构都是必需的，但在四面体位点进行高亲和力金属结合时两者都不是必需的。该结构表明，一个双结构域蛋白片段和一个双链DNA结合位点可能与一个共同的双折叠轴相互作用，该轴连接两个结构域和DNA反向重复序列的两个半位点。
