Characterization of the Bacillus subtilis Penicillin-Binding Protein PBP4

• 作者: Arnaud Vanden Broeck Bernard Joris Colette Duez Eric Sauvage
• 来源期刊: 微生物学(英文)
• 学科: 医学
• 关键词: B. SUBTILIS PBP4* Class-C PBP D-Stereospecific ESTERASE
• 年，卷（期）: 2019,（3）
• 页码范围: 164-176
• 页数: 13页
• 分类号: R73

摘要

Purpose: The PBP4* is a Penicillin Binding Protein belonging to the class C of AmpH type whose function remains poorly understood. This study aimed to evaluate the biophysical and enzymatic properties of the Bacillus subtilis PBP4* to gain insights into its role in the context of bacterial cell wall recycling. Methods: To characterize the PBP4*, the full-length PBP4* and its N-terminal penicillin-binding domain have been produced in Escherichia coli and purified. Results: A comparison of biophysical properties has shown that both recombinant proteins are monomeric in solution and retain the same thermal stability. On the other hand, the D-alanine methyl esterase activity detected with the full-length PBP4* is impeded by the cleavage of the 92 amino acid C-terminal domain. The esterase activity of the full-length PBP4* strates a clear D-stereospecificity. The PBP4* is also active on B. subtilis cell walls bearing teichoic acids, compounds commonly substituted with D-alanine residues. Conclusions: Our results are in agreement with the hypothesis that PBP4* could play a role in recycling cell wall components, as previously suggested.