Metallo-beta-lactamase fold containing family
metallo-beta-lactamase fold containing family
The metallo-β-lactamase (MBL) superfamily constitutes a group of proteins found in all domains of life that share a characteristic αββα fold with the ability to bind transition metal ions. Such metal binding sites may have divalent transition metal ions like Zn(II), Fe(II)/Fe(III) and Mn(II), and are located at the bottom of a wide cleft able to accommodate diverse substrates. The name was adopted after the first members of the superfamily to be studied experimentally: a group of zinc-dependent hydrolytic enzymes conferring bacterial resistance to β-lactam antibiotics.    Proteins belonging to the MBL superfamily usually combine at least one MBL domain with additional domains that provide different functions, such as substrate recognition or binding to other polypeptides, in a modular fashion. Thus, MBL superfamily members grasp the metal-assisted water-activation ability of the MBL domain in order to perform a wide variety of hydrolytic reactions.