Download MendeleyStructural basis of peptide secretion for Quorum sensing by ComA.
Yu, L., Xu, X., Chua, W.Z., Feng, H., Ser, Z., Shao, K., Shi, J., Wang, Y., Li, Z., Sobota, R.M., Sham, L.T., Luo, M.(2023) Nat Commun 14: 7178-7178
- PubMed: 37935699
- DOI: https://doi.org/10.1038/s41467-023-42852-9
- Primary Citation of Related Structures:
8HF4, 8HF5, 8HF6, 8HF7, 8K4B, 8K7A - PubMed Abstract:
Quorum sensing (QS) is a crucial regulatory mechanism controlling bacterial signalling and holds promise for novel therapies against antimicrobial resistance. In Gram-positive bacteria, such as Streptococcus pneumoniae, ComA is a conserved efflux pump responsible for the maturation and secretion of peptide signals, including the competence-stimulating peptide (CSP), yet its structure and function remain unclear. Here, we functionally characterize ComA as an ABC transporter with high ATP affinity and determined its cryo-EM structures in the presence or absence of CSP or nucleotides. Our findings reveal a network of strong electrostatic interactions unique to ComA at the intracellular gate, a putative binding pocket for two CSP molecules, and negatively charged residues facilitating CSP translocation. Mutations of these residues affect ComA's peptidase activity in-vitro and prevent CSP export in-vivo. We demonstrate that ATP-Mg 2+ triggers the outward-facing conformation of ComA for CSP release, rather than ATP alone. Our study provides molecular insights into the QS signal peptide secretion, highlighting potential targets for QS-targeting drugs.
Organizational Affiliation:
Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, 117543, Singapore.
