The enzyme catalyzes the hydrolysis of the C-N bond in beta-lactam compounds determining the inactivation of such antibiotics. Members of the beta-lactamase family have been grouped into four classes (A, B, C, D). Class B members employ either one (see M0016 entry) or two zinc ions in a dinuclear site (see M0015 entry) to effect beta-lactam cleavage (PMID10508665).
ZN 2 A IN THE RESTING STATE ENZYME
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Representative PDB structure for ZN 2 A in the resting state enzyme | |
| PDB code | 1x8g | |
| Metal Type in the PDB | zinc | |
| Residue name of the metal in the PDB | ZN | |
| Residue number of the metal in the PDB | 401 | |
| Chain of the metal in the PDB | A | |
| Atom name of the metal in the PDB | ZN | |
| Download the coordinates file of the metal site | NOTES ON PDB: In this example (1x8g), zinc is coordinated by the residues forming the bypiramidal trigonal site in the di-zinc form (Asp, Cys, His). This is probably due to the fact that this protein lacks one of the His of the tetrahedral site. There are also examples of structures of mono-zinc beta-lactamases where the metal occupies the tetrahedral site (e.g. 1BMC). | |
| First Coordination Sphere | ||||||
| Ligand Type | Ligand Identity | Residue In MACiE | Donors | Bind Mode | Catalytic? | Notes |
| residue | ASP 120 A | ASP 90 A | OD2 | monodentate | Yes | Asp90 is involved in proton relay |
| residue | CYS 221 A | CYS 168 A | SG | monodentate | No | - |
| residue | HIS 263 A | His 210 A | NE2 | monodentate | No | - |
| artifact | CO3 2 _ | - | O1 | monodentate | No | This carbonate has probably no physiological role (PMID15588826). |