Metal ion binding and enzymatic mechanism of Methanococcus jannaschii RNase HII

Research demonstrates that the catalysis of RNase HII of Methanococcus jannaschii is mediated by one metal binding to the enzyme and concomittant substrate binding positions the metal ion. Amino acid residue Asp149 is required for the enzyme activity. Data show that metal binding occurs on three sites and the fourth site is involved with the substrate interaction.