ZINC, A STRUCTURAL COMPONENT OF ADENYLATE KINASES FROM GRAM-POSITIVE BACTERIA

The recent finding that Bacillus stearothermophilus adenylate kinase c ontains a zinc atom coordinated to four cysteines prompted us to inves tigate the metal-binding properties of the enzyme from various bacteri a. We conclude that zinc was present only in adenylate kinase from gra m-positive species and that this property is correlated with the prese nce of three or four Cys residues in the sequence Cys-X2-Cys-X16-Cys-X 2-Cys/Asp, in which X stands for different amino acid residues.