Apart from the beta-lactamases and metallo-beta-lactamases, a number of other proteins contain this domain [<cite idref="PUB00001273"/>]. These proteins include thiolesterases, members of the glyoxalase II family,that catalyse the hydrolysis of S-D-lactoyl-glutathione to form glutathione and D-lactic acid and a competence protein that is essential for natural transformation in <taxon tax_id="485">Neisseria gonorrhoeae</taxon> and could be a transporter involved in DNA uptake. Except for the competence protein these proteins bind two zinc ions per molecule as cofactor. Beta-lactamase-like