Invited Speaker Australian Society for Microbiology Annual Scientific Meeting 2023

The Suppressor of copper sensitivity protein C from Caulobacter crescentus is a trimeric disulfide isomerase         (93935)

Guillaume A Petit 1 , Yaoqin Hong 2 , Karrera Y Djoko 3 , Andrew E Whitten 4 , Emily J Furlong 5 , Airlie McCoy 6 , Jacqueline M Gulbis 7 , Makrina Totsika 2 , Jennifer L Martin 1 8 , Maria A Halili 1
  1. Griffith University, Nathan, QLD, Australia
  2. Queensland University of Technology, Brisbane, Queensland, Australia
  3. Durham University, Durham, United Kingdom
  4. Australian Nuclear Science and Technology Organization, Lucas Heights, NSW, Australia
  5. Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
  6. University of Cambridge, Cambridge, United Kingdom
  7. The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
  8. University of Wollongong, Wollongong, NSW, Australia

The introduction of disulfide bonds to newly synthesised proteins is a critical process in Gram-negative bacteria. Disulfide bonds are critical to the structure and function of many proteins, including virulence factors. Understanding the pathways which are involved in the formation and regulation of disulfide bonds is key to our understanding, and aids in the development of novel treatment strategies to combat pathogenic bacteria [1].

The well-characterised disulfide bond forming (DSB) proteins play an essential role in the formation or isomerisation of disulfide bonds. The suppressor of copper sensitivity C (ScsC) proteins, part of the bacterial copper-resistance response, share structural and functional similarities to the DSB proteins. However, ScsC differs from DSB in that the function of SscC is dependent on its oligomeric state. We used mass photometry and small-angle X-ray scattering to show that the protein forms a trimeric conformation. A crystal structure was also determined, indicating that the trimeric state was formed via the N-terminal alpha-helical domains of three ScsC protomers. The knowledge from this structure contributes to our understanding of a new family of proteins involved in disulfide bond formation in bacteria [2].

 

  1. Landeta, C., D. Boyd, and J. Beckwith, Disulfide bond formation in prokaryotes. Nat Microbiol, 2018. 3(3): p. 270-280.
  2. Petit, G.A., et al., The suppressor of copper sensitivity protein C from Caulobacter crescentus is a trimeric disulfide isomerase that binds copper(I) with subpicomolar affinity. Acta Crystallogr D Struct Biol, 2022. 78(Pt 3): p. 337-352.