1CHC

STRUCTURE OF THE C3HC4 DOMAIN BY 1H-NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; A NEW STRUCTURAL CLASS OF ZINC-FINGER

Summary for 1CHC

• Entry DOI: 10.2210/pdb1chc/pdb
• Descriptor: EQUINE HERPES VIRUS-1 RING DOMAIN, ZINC ION (2 entities in total)
• Functional Keywords: viral protein
• Biological source: Equid herpesvirus 1 (Equine herpesvirus 1)
• Total number of polymer chains: 1
• Total formula weight: 7782.70

Authors

Barlow, P.N.,Everett, R.D.,Luisi, B. (deposition date: 1994-02-02, release date: 1994-04-30, Last modification date: 2024-05-22)

Primary citation

Barlow, P.N.,Luisi, B.,Milner, A.,Elliott, M.,Everett, R.
Structure of the C3HC4 domain by 1H-nuclear magnetic resonance spectroscopy. A new structural class of zinc-finger.
J.Mol.Biol., 237:201-211, 1994

PubMed Abstract: A recently identified sequence motif, referred to as "C3HC4" (also "RING finger" and "A Box") for its distinctive pattern of putative metal-binding residues, has been found in a wide range of proteins. In a previous paper we described the expression and purification of fragments encompassing this motif from the Vmw110 (IPC0) protein family. We showed that the equine herpes virus protein binds zinc ions and adopts a beta beta alpha beta fold. We now report the tertiary structure of this domain in solution, as determined by two-dimensional 1H-NMR An amphipathic alpha-helix lies along one surface of a triple-stranded beta-sheet. Four pairs of metal-binding residues sequester two zincs at distinct tetrahedral sites. The first and third pairs bind one metal ion, while the second and fourth pairs bind the other, forming an interleaved whole. The first and the fourth pairs are contained within two prominent, well-defined loops related by an approximate dyad symmetry. Conserved residues within the helix, sheet and loops contribute to a compact hydrophobic core. The region comprising the first two beta-strands and the alpha-helix has remarkable structural similarity with a TFIIIA type of zinc finger, even though the C3HC4 domain appears not to bind specifically to DNA or RNA. Using site-directed mutagenesis we demonstrate that exposed polar side-chains of the C3HC4 alpha-helix are essential for trans-activation of gene expression by an intact herpes virus regulatory protein.

PubMed: 8126734
DOI: 10.1006/jmbi.1994.1222

Experimental method

SOLUTION NMR