3I15

Cobalt-substituted metallo-beta-lactamase from Bacillus cereus: residue Cys168 fully oxidized

Summary for 3I15

• Entry DOI: 10.2210/pdb3i15/pdb
• Related: 1bc2 1bvt 3I0V 3I11 3I13 3I14
• Descriptor: Beta-lactamase 2, COBALT (II) ION (3 entities in total)
• Functional Keywords: antibiotic resistance, metallo-beta-lactamase superfamily, zn-dependent hydrolase, hydrolase, metal-binding
• Biological source: Bacillus cereus
• Total number of polymer chains: 1
• Total formula weight: 25102.46

Authors

Gonzalez, J.M.,Buschiazzo, A.,Vila, A.J. (deposition date: 2009-06-25, release date: 2009-12-29, Last modification date: 2011-07-13)

Primary citation

Gonzalez, J.M.,Buschiazzo, A.,Vila, A.J.
Evidence of adaptability in metal coordination geometry and active-site loop conformation among B1 metallo-beta-lactamases .
Biochemistry, 49:7930-7938, 2010

PubMed Abstract: Subclass B1 beta-lactamases are Zn(II)-dependent hydrolases that confer bacterial resistance to most clinically useful beta-lactam antibiotics. The enzyme BcII from Bacillus cereus is a prototypical enzyme that belongs to this group, the first Zn(II)-dependent beta-lactamase to be discovered. Crucial aspects of the BcII catalytic mechanism and metal binding mode have been assessed mostly on the Co(II)-substituted surrogate. Here we report a high-resolution structure of Co(II)-BcII, revealing a metal coordination geometry identical to that of the native zinc enzyme. In addition, a high-resolution structure of the apoenzyme, together with structures with different degrees of metal occupancy and oxidation levels of a conserved Cys ligand, discloses a considerable mobility of two loops containing four metal ligands (namely, regions His116-Arg121 and Gly219-Cys221). This flexibility is expected to assist in the structural rearrangement of the metal sites during catalytic turnover, which, along with the coordination geometry adaptability of Zn(II) ions, grants the interaction with a variety of substrates, a characteristic feature of B1 metallo-beta-lactamases.

PubMed: 20677753
DOI: 10.1021/bi100894r

Experimental method

X-RAY DIFFRACTION (1.55 Å)