8K7A
Cryo-EM structure of nucleotide-bound ComA E647Q mutant with Mg2+
Summary for 8K7A
| Entry DOI | 10.2210/pdb8k7a/pdb |
| EMDB information | 34712 34713 36936 |
| Descriptor | Transport/processing ATP-binding protein ComA, ADENOSINE-5'-TRIPHOSPHATE, MAGNESIUM ION (3 entities in total) |
| Functional Keywords | abc transporter, pcat, transport protein |
| Biological source | Streptococcus pneumoniae R6 |
| Total number of polymer chains | 2 |
| Total formula weight | 161927.05 |
| Authors | |
| Primary citation | 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. Structural basis of peptide secretion for Quorum sensing by ComA. Nat Commun, 14:7178-7178, 2023 Cited by 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 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. PubMed: 37935699DOI: 10.1038/s41467-023-42852-9 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (4.2 Å) |
Structure validation
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