6XRB

Crystal structure of SciW from Salmonella typhimurium

Summary for 6XRB

• Entry DOI: 10.2210/pdb6xrb/pdb
• Related: 6XRF 6XRR
• Descriptor: SciW, TRIETHYLENE GLYCOL, ... (4 entities in total)
• Functional Keywords: sciw, type vi secretion, t6ss, chaperone
• Biological source: Salmonella typhimurium (strain SL1344); More
• Total number of polymer chains: 2
• Total formula weight: 34272.69

Authors

Sachar, K.,Ahmad, S.,Whitney, J.C.,Prehna, G. (deposition date: 2020-07-11, release date: 2020-12-30, Last modification date: 2024-10-16)

Primary citation

Ahmad, S.,Tsang, K.K.,Sachar, K.,Quentin, D.,Tashin, T.M.,Bullen, N.P.,Raunser, S.,McArthur, A.G.,Prehna, G.,Whitney, J.C.
Structural basis for effector transmembrane domain recognition by type VI secretion system chaperones.
Elife, 9:-, 2020

PubMed Abstract: Type VI secretion systems (T6SSs) deliver antibacterial effector proteins between neighboring bacteria. Many effectors harbor N-terminal ransembrane omains (TMDs) implicated in effector translocation across target cell membranes. However, the distribution of these TMD-containing effectors remains unknown. Here, we discover prePAAR, a conserved motif found in over 6000 putative TMD-containing effectors encoded predominantly by 15 genera of Proteobacteria. Based on differing numbers of TMDs, effectors group into two distinct classes that both require a member of the Eag family of T6SS chaperones for export. Co-crystal structures of class I and class II effector TMD-chaperone complexes from Typhimurium and , respectively, reveals that Eag chaperones mimic transmembrane helical packing to stabilize effector TMDs. In addition to participating in the chaperone-TMD interface, we find that prePAAR residues mediate effector-VgrG spike interactions. Taken together, our findings reveal mechanisms of chaperone-mediated stabilization and secretion of two distinct families of T6SS membrane protein effectors.

PubMed: 33320089
DOI: 10.7554/eLife.62816

Experimental method

X-RAY DIFFRACTION (1.76 Å)