Measles Virus V Protein Binds Zinc

Measles virus transcription generates multiple P/C gene-specific mRNAs by a process which has been termed editing. In one of these mRNAs, the cotranscriptional addition of a single nontemplated G residue allows translational access to the V protein reading frame. The protein translated from this mRNA has been called V and consists of 231 amino-terminal amino acid residues identical to those at the amino terminus of the P protein followed by a unique carboxy-terminal domain consisting of 68 amino acids from the V reading frame. The most striking feature of this unique domain is the presence within it of seven cysteine residues whose presence and position are highly conserved among different paramyxoviruses. The number and arrangement of these cysteine residues is suggestive of a zinc finger protein. We have used a zinc binding protocol to determine that V protein does indeed bind zinc, have further demonstrated that this metal binding activity is highly specific to zinc, and have shown that it is the unique carboxy-terminal domain of the V protein that is responsible for zinc binding.