Poster Presentation The 45th Lorne Conference on Protein Structure and Function 2020

Structural and functional characterization of the C-terminal domains of CzcD proteins (#215)

Saumya R Udagedara 1 , Daniel M La Porta 2 , Christian Spehar 2 , Ghruta Purohit 2 , Matthew Hein 2 , Monique Fatmous 2 , Patricia Casas Garcia 2 , Christopher McDevitt 3 , Megan Maher 1
  1. School of Chemistry, The Bio21 Institute, University of Melbourne, Melbourne, VIC, Australia
  2. Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
  3. Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia

Zinc (Zn) is the second most abundant transition metal ion in humans and is also a potent antimicrobial component of the innate immune response at the host pathogen interface. Bacteria subvert or resist host Zn insults by metal efflux pathways that include cation diffusion facilitator (CDF) proteins. The structural and functional examination of this protein family has been limited, with only the structures of the YiiP proteins from Escherichia coli (PDB 3H90) [1] and Shewanella oneidensis (PDB 5VRF) [2] described to date.

 

In this work, we have targeted the C-terminal domains of the CzcD proteins from Cupriavidus metallidurans, Pseudomonas aeruginosa and Thermotoga maritima for structural and functional analysis. We have determined the metal binding properties, solution quaternary structures and three-dimensional architectures of these proteins and revealed remarkable similarity in protein structures but significant diversity in the metal-binding properties. Further we have discovered a potential novel mechanism for metal-promoted dimerization for the Cupriavidus metallidurans and Pseudomonas aeruginosa proteins. This poster will present our findings on structural characterisation and metal-binding properties of these CzcD proteins for better understanding of CDF family of proteins.

  1. [1]. Lu, M., J. Chai, and D. Fu, Structural basis for autoregulation of the zinc transporter YiiP. Nat Struct Mol Biol, 2009. 16(10): p. 1063-7. [2]. Lopez-Redondo, M.L., et al., Structural basis for the alternating access mechanism of the cation diffusion facilitator YiiP. Proc Natl Acad Sci U S A, 2018.