5B3R

Crystal structure of metallo-beta-lactamase IMP-18 from Pseudomonas aeruginosa

Summary for 5B3R

• Entry DOI: 10.2210/pdb5b3r/pdb
• Descriptor: IMP-18, ZINC ION, CITRIC ACID, ... (4 entities in total)
• Functional Keywords: metallo-beta-lactamase, hydrolase, antibiotic resistance
• Biological source: Pseudomonas aeruginosa
• Total number of polymer chains: 2
• Total formula weight: 51085.21

Authors

Shimizu-Ibuka, A.,Ishii, Y. (deposition date: 2016-03-10, release date: 2017-02-15, Last modification date: 2024-03-20)

Primary citation

Furuyama, T.,Nonomura, H.,Ishii, Y.,Hanson, N.D.,Shimizu-Ibuka, A.
Structural and Mutagenic Analysis of Metallo-beta-Lactamase IMP-18
Antimicrob. Agents Chemother., 60:5521-5526, 2016

PubMed Abstract: IMP-type metallo-β-lactamases (MBLs) are exogenous zinc metalloenzymes that hydrolyze a broad range of β-lactams, including carbapenems. Here we report the crystal structure of IMP-18, an MBL cloned from Pseudomonas aeruginosa, at 2.0-Å resolution. The overall structure of IMP-18 resembles that of IMP-1, with an αβ/βα "folded sandwich" configuration, but the loop that covers the active site has a distinct conformation. The relationship between IMP-18's loop conformation and its kinetic properties was investigated by replacing the amino acid residues that can affect the loop conformation (Lys44, Thr50, and Ile69) in IMP-18 with those occupying the corresponding positions in the well-described enzyme IMP-1. The replacement of Thr50 with Pro considerably modified IMP-18's kinetic properties, specifically those pertaining to meropenem, with the kcat/Km value increased by an order of magnitude. The results indicate that this is a key residue that defines the kinetic properties of IMP-type β-lactamases.

PubMed: 27381398
DOI: 10.1128/AAC.00985-16

Experimental method

X-RAY DIFFRACTION (2 Å)