8SXH
Structure of the C-terminal protease CtpA-LbcA complex of Pseudomonas aeruginosa
Summary for 8SXH
| Entry DOI | 10.2210/pdb8sxh/pdb |
| EMDB information | 40852 |
| Descriptor | Carboxyl-terminal protease, TPR repeat-containing protein PA4667, unidentified peptide (3 entities in total) |
| Functional Keywords | ctpa, lbca, c-terminal protease, pseudomonas aeruginosa, hydrolase |
| Biological source | Pseudomonas aeruginosa More |
| Total number of polymer chains | 12 |
| Total formula weight | 444590.07 |
| Authors | Hsu, H.-C.,Li, H. (deposition date: 2023-05-22, release date: 2024-03-06, Last modification date: 2024-04-24) |
| Primary citation | Hsu, H.C.,Wang, M.,Kovach, A.,Darwin, A.J.,Li, H. P. aeruginosa CtpA protease adopts a novel activation mechanism to initiate the proteolytic process. Embo J., 43:1634-1652, 2024 Cited by PubMed Abstract: During bacterial cell growth, hydrolases cleave peptide cross-links between strands of the peptidoglycan sacculus to allow new strand insertion. The Pseudomonas aeruginosa carboxyl-terminal processing protease (CTP) CtpA regulates some of these hydrolases by degrading them. CtpA assembles as an inactive hexamer composed of a trimer-of-dimers, but its lipoprotein binding partner LbcA activates CtpA by an unknown mechanism. Here, we report the cryo-EM structures of the CtpA-LbcA complex. LbcA has an N-terminal adaptor domain that binds to CtpA, and a C-terminal superhelical tetratricopeptide repeat domain. One LbcA molecule attaches to each of the three vertices of a CtpA hexamer. LbcA triggers relocation of the CtpA PDZ domain, remodeling of the substrate binding pocket, and realignment of the catalytic residues. Surprisingly, only one CtpA molecule in a CtpA dimer is activated upon LbcA binding. Also, a long loop from one CtpA dimer inserts into a neighboring dimer to facilitate the proteolytic activity. This work has revealed an activation mechanism for a bacterial CTP that is strikingly different from other CTPs that have been characterized structurally. PubMed: 38467832DOI: 10.1038/s44318-024-00069-6 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.94 Å) |
Structure validation
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