Crystal structure of PA0833 periplasmic domain from Pseudomonas aeruginosa reveals an unexpected enlarged peptidoglycan binding pocket.
Lin, X., Ye, F., Lin, S., Yang, F., Chen, Z., Cao, Y., Chen, Z., Gu, J., Lu, G.(2019) Biochem Biophys Res Commun 511: 875-881
- PubMed: 30850161 
- DOI: https://doi.org/10.1016/j.bbrc.2019.02.104
- Primary Citation of Related Structures:  
6JFW - PubMed Abstract: 
PA0833 of Pseudomonas aeruginosa is recently identified as an OmpA C-like protein that is able to interact with bacterial peptidoglycan (PGN). In this study, we reported the biochemical and structural characterization of the PGN-binding periplasmic-domain of PA0833 (PA0833-PD). Via mutagenesis, key residues responsible for engaging PGN were identified, which also enables us to localize the PGN-binding pocket in a 2.0 Å crystal structure solved in this study. In contrast to its homologous proteins (as represented by AbOmpA-PD of Acinetobacter baumannii) that interact with PGN by directly engaging the DAP (diaminopimelate) moiety, PA0833-PD exhibits an enlarged PGN-binding pocket due to residue insertions and the formation of an extra α-helix in one lateral side of the pocket. Accordingly, single DAP molecule does not show detectable interactions with PA0833-PD in solution, highlighting that other PGN-components, in addition to DAP, are also required to restore the full binding capacity observed between PA0833 and PGN.
Organizational Affiliation: 
West China Hospital Emergency Department (WCHED), State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu, Sichuan, 610041, China.