Structural insights into the function of type VI secretion system TssA subunits

DOI: 10.1038/s41467-018-07247-1

Authors: Samuel R. Dix (University of Sheffield) , Hayley J. Owen (University of Sheffield) , Ruyue Sun (University of Sheffield Medical School) , Asma Ahmad (University of Sheffield Medical School) , Sravanthi Shastri (University of Sheffield Medical School) , Helena L. Spiewak (University of Sheffield Medical School; Newcastle upon Tyne Hospitals NHS Foundation Trust) , Daniel J. Mosby (University of Sheffield Medical School) , Matthew J. Harris (University of Sheffield) , Sarah L. Batters (University of Sheffield Medical School) , Thomas A. Brooker (University of Sheffield Medical School) , Svetomir B. Tzokov (University of Sheffield) , Svetlana E. Sedelnikova (University of Sheffield) , Patrick J. Baker (University of Sheffield) , Per A. Bullough (University of Sheffield) , David W. Rice (University of Sheffield) , Mark S. Thomas (University of Sheffield Medical School)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Communications , VOL 9

State: Published (Approved)
Published: November 2018
Diamond Proposal Number(s): 8987 , 12788 , 17773

Abstract: The type VI secretion system (T6SS) is a multi-protein complex that injects bacterial effector proteins into target cells. It is composed of a cell membrane complex anchored to a contractile bacteriophage tail-like apparatus consisting of a sharpened tube that is ejected by the contraction of a sheath against a baseplate. We present structural and biochemical studies on TssA subunits from two different T6SSs that reveal radically different quaternary structures in comparison to the dodecameric E. coli TssA that arise from differences in their C-terminal sequences. Despite this, the different TssAs retain equivalent interactions with other components of the complex and position their highly conserved N-terminal ImpA_N domain at the same radius from the centre of the sheath as a result of their distinct domain architectures, which includes additional spacer domains and highly mobile interdomain linkers. Together, these variations allow these distinct TssAs to perform a similar function in the complex.

Journal Keywords: Protein translocation; X-ray crystallography

Diamond Keywords: Bacteriophages; Viruses

Subject Areas: Biology and Bio-materials


Instruments: I02-Macromolecular Crystallography , I03-Macromolecular Crystallography , I04-1-Macromolecular Crystallography (fixed wavelength) , I04-Macromolecular Crystallography , I24-Microfocus Macromolecular Crystallography

Added On: 19/11/2018 11:08

Discipline Tags:

Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)