7MU9

Solution NMR structure of the XVIPCD region from the T4SS effector X-Tfe(XAC2609) from Xanthomonas citri

Summary for 7MU9

• Entry DOI: 10.2210/pdb7mu9/pdb
• NMR Information: BMRB: 30908
• Descriptor: VirD4 interacting protein conserved domain (1 entity in total)
• Functional Keywords: bacterial toxin, bacterial competition, type iv secretion system, vird4 binding module, transport protein
• Biological source: Xanthomonas axonopodis pv. citri (strain 306)
• Total number of polymer chains: 1
• Total formula weight: 11480.57

Authors

Oka, G.U.,Salinas, R.K.,Farah, C.S. (deposition date: 2021-05-14, release date: 2021-12-22, Last modification date: 2024-05-15)

Primary citation

Oka, G.U.,Souza, D.P.,Cenens, W.,Matsuyama, B.Y.,Cardoso, M.V.C.,Oliveira, L.C.,da Silva Lima, F.,Cuccovia, I.M.,Guzzo, C.R.,Salinas, R.K.,Farah, C.S.
Structural basis for effector recognition by an antibacterial type IV secretion system.
Proc.Natl.Acad.Sci.USA, 119:-, 2022

PubMed Abstract: Many soil-, water-, and plant-associated bacterial species from the orders Xanthomonadales, Burkholderales, and Neisseriales carry a type IV secretion system (T4SS) specialized in translocating effector proteins into other gram-negative species, leading to target cell death. These effectors, known as X-Tfes, carry a carboxyl-terminal domain of ∼120 residues, termed XVIPCD, characterized by several conserved motifs and a glutamine-rich tail. Previous studies showed that the XVIPCD is required for interaction with the T4SS coupling protein VirD4 and for T4SS-dependent translocation. However, the structural basis of the XVIPCD-VirD4 interaction is unknown. Here, we show that the XVIPCD interacts with the central all-alpha domain of VirD4 (VirD4). We used solution NMR spectroscopy to solve the structure of the XVIPCD of X-Tfe from and to map its interaction surface with VirD4 Isothermal titration calorimetry and in vivo versus competition assays using wild-type and mutant X-Tfe and X-Tfe indicate that XVIPCDs can be divided into two regions with distinct functions: the well-folded N-terminal region contains specific conserved motifs that are responsible for interactions with VirD4, while both N- and carboxyl-terminal regions are required for effective X-Tfe translocation into the target cell. The conformational stability of the N-terminal region is reduced at and below pH 7.0, a property that may facilitate X-Tfe unfolding and translocation through the more acidic environment of the periplasm.

PubMed: 34983846
DOI: 10.1073/pnas.2112529119

Experimental method

SOLUTION NMR