4YFM

Class A beta-lactamase from Mycobacterium abscessus

4YFM の概要

• エントリーDOI: 10.2210/pdb4yfm/pdb
• 分子名称: Beta-lactamase, ACETATE ION, GLYCEROL, ... (4 entities in total)
• 機能のキーワード: beta-lactamase, clavulanate, carbapenem, mycobacterium tuberculosis, hydrolase
• 由来する生物種: Mycobacterium abscessus
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 60570.15

構造登録者

Soroka, D.,Li de la Sierra-Gallay, I.,Dubee, V.,van Tilbeurgh, H.,Arthur, M. (登録日: 2015-02-25, 公開日: 2015-07-22, 最終更新日: 2024-01-10)

主引用文献

Soroka, D.,Li de la Sierra-Gallay, I.,Dubee, V.,Triboulet, S.,van Tilbeurgh, H.,Compain, F.,Ballell, L.,Barros, D.,Mainardi, J.L.,Hugonnet, J.E.,Arthur, M.
Hydrolysis of Clavulanate by Mycobacterium tuberculosis beta-Lactamase BlaC Harboring a Canonical SDN Motif.
Antimicrob.Agents Chemother., 59:5714-5720, 2015

PubMed Abstract: Combinations of β-lactams with clavulanate are currently being investigated for tuberculosis treatment. Since Mycobacterium tuberculosis produces a broad spectrum β-lactamase, BlaC, the success of this approach could be compromised by the emergence of clavulanate-resistant variants, as observed for inhibitor-resistant TEM variants in enterobacteria. Previous analyses based on site-directed mutagenesis of BlaC have led to the conclusion that this risk was limited. Here, we used a different approach based on determination of the crystal structure of β-lactamase BlaMAb of Mycobacterium abscessus, which efficiently hydrolyzes clavulanate. Comparison of BlaMAb and BlaC allowed for structure-assisted site-directed mutagenesis of BlaC and identification of the G(132)N substitution that was sufficient to switch the interaction of BlaC with clavulanate from irreversible inactivation to efficient hydrolysis. The substitution, which restored the canonical SDN motif (SDG→SDN), allowed for efficient hydrolysis of clavulanate, with a more than 10(4)-fold increase in k cat (0.41 s(-1)), without affecting the hydrolysis of other β-lactams. Mass spectrometry revealed that acylation of BlaC and of its G(132)N variant by clavulanate follows similar paths, involving sequential formation of two acylenzymes. Decarboxylation of the first acylenzyme results in a stable secondary acylenzyme in BlaC, whereas hydrolysis occurs in the G(132)N variant. The SDN/SDG polymorphism defines two mycobacterial lineages comprising rapidly and slowly growing species, respectively. Together, these results suggest that the efficacy of β-lactam-clavulanate combinations may be limited by the emergence of resistance. β-Lactams active without clavulanate, such as faropenem, should be prioritized for the development of new therapies.

PubMed: 26149997
DOI: 10.1128/AAC.00598-15

実験手法

X-RAY DIFFRACTION (1.4 Å)