4NQ6

Bacillus cereus Zn-dependent metallo-beta-lactamase at pH 7 complexed with compound L-CS319

Summary for 4NQ6

• Entry DOI: 10.2210/pdb4nq6/pdb
• Related: 4NQ4 4NQ5 4NQ6 4NQ7
• Descriptor: Beta-lactamase 2, ZINC ION, POTASSIUM ION, ... (5 entities in total)
• Functional Keywords: lactamase, metallo-beta-lactamase superfamily, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• Biological source: Bacillus cereus
• Cellular location: Periplasm : P04190
• Total number of polymer chains: 1
• Total formula weight: 24830.18

Authors

Gonzalez, J.M.,Gonzalez, M.M.,Vila, A.J. (deposition date: 2013-11-23, release date: 2014-11-26, Last modification date: 2024-02-28)

Primary citation

Hinchliffe, P.,Gonzalez, M.M.,Mojica, M.F.,Gonzalez, J.M.,Castillo, V.,Saiz, C.,Kosmopoulou, M.,Tooke, C.L.,Llarrull, L.I.,Mahler, G.,Bonomo, R.A.,Vila, A.J.,Spencer, J.
Cross-class metallo-beta-lactamase inhibition by bisthiazolidines reveals multiple binding modes.
Proc. Natl. Acad. Sci. U.S.A., 113:E3745-E3754, 2016

PubMed Abstract: Metallo-β-lactamases (MBLs) hydrolyze almost all β-lactam antibiotics and are unaffected by clinically available β-lactamase inhibitors (βLIs). Active-site architecture divides MBLs into three classes (B1, B2, and B3), complicating development of βLIs effective against all enzymes. Bisthiazolidines (BTZs) are carboxylate-containing, bicyclic compounds, considered as penicillin analogs with an additional free thiol. Here, we show both l- and d-BTZ enantiomers are micromolar competitive βLIs of all MBL classes in vitro, with Kis of 6-15 µM or 36-84 µM for subclass B1 MBLs (IMP-1 and BcII, respectively), and 10-12 µM for the B3 enzyme L1. Against the B2 MBL Sfh-I, the l-BTZ enantiomers exhibit 100-fold lower Kis (0.26-0.36 µM) than d-BTZs (26-29 µM). Importantly, cell-based time-kill assays show BTZs restore β-lactam susceptibility of Escherichia coli-producing MBLs (IMP-1, Sfh-1, BcII, and GOB-18) and, significantly, an extensively drug-resistant Stenotrophomonas maltophilia clinical isolate expressing L1. BTZs therefore inhibit the full range of MBLs and potentiate β-lactam activity against producer pathogens. X-ray crystal structures reveal insights into diverse BTZ binding modes, varying with orientation of the carboxylate and thiol moieties. BTZs bind the di-zinc centers of B1 (IMP-1; BcII) and B3 (L1) MBLs via the free thiol, but orient differently depending upon stereochemistry. In contrast, the l-BTZ carboxylate dominates interactions with the monozinc B2 MBL Sfh-I, with the thiol uninvolved. d-BTZ complexes most closely resemble β-lactam binding to B1 MBLs, but feature an unprecedented disruption of the D120-zinc interaction. Cross-class MBL inhibition therefore arises from the unexpected versatility of BTZ binding.

PubMed: 27303030
DOI: 10.1073/pnas.1601368113

Experimental method

X-RAY DIFFRACTION (1.8 Å)