The metallo-beta-lactamase protein fold is a protein domain

Protein domain

A protein domain is a part of protein sequence and structure that can evolve, function, and exist independently of the rest of the protein chain. Each domain forms a compact three-dimensional structure and often can be independently stable and folded. Many proteins consist of several structural...

 contained in class B beta-lactamase

Beta-lactamase

Beta-lactamases are enzymes produced by some bacteria and are responsible for their resistance to beta-lactam antibiotics like penicillins, cephamycins, and carbapenems . These antibiotics have a common element in their molecular structure: a four-atom ring known as a beta-lactam...

s and a number of other proteins
.
These proteins include thiolesterase

Glutathione thiolesterase

In enzymology, a glutathione thiolesterase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are S-acylglutathione and H2O, whereas its two products are glutathione and carboxylate....

s, members of the glyoxalase II

Hydroxyacylglutathione hydrolase

In enzymology, a Hydroxyacylglutathione hydrolase is an enzyme that catalyzes the chemical reactionHence, this enzyme has two substrate, -S-lactoylglutathione and water, and two products, glutathione and a 2-hydroxy carboxylate...

 family, that catalyse the hydrolysis of S-D-lactoyl-glutathione to form glutathione

Glutathione

Glutathione is a tripeptide that contains an unusual peptide linkage between the amine group of cysteine and the carboxyl group of the glutamate side-chain...

 and D-lactic acid

Lactic acid

Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...

 and a competence protein that is essential for natural transformation in Neisseria gonorrhoeae

Neisseria gonorrhoeae

Neisseria gonorrhoeae, also known as gonococci , or gonococcus , is a species of Gram-negative coffee bean-shaped diplococci bacteria responsible for the sexually transmitted infection gonorrhea.N...

and could be a transporter involved in DNA uptake. Except for the competence protein these proteins bind two zinc

Zinc

Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

 ions per molecule as cofactor

Cofactor (biochemistry)

A cofactor is a non-protein chemical compound that is bound to a protein and is required for the protein's biological activity. These proteins are commonly enzymes, and cofactors can be considered "helper molecules" that assist in biochemical transformations....

.

Metallo-beta-lactamases are important enzymes because they are involved in the breakdown of antibiotics by antibiotic-resistant bacteria.