Poster Presentation Melbourne Protein Group Student Symposium 2013

Structural studies on the nucleotide-binding protein (PsaB) from the ABC transporter PsaBCA. (#73)

Mwilye Sikanyika 1 , Christopher A McDevitt 2 , Megan J Maher 1
  1. Biochemistry, La Trobe University, Bundoora, Victoria
  2. School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, South Australia

Bacterial antibiotic resistance is an increasing threat to human health. The over-reliance on antibiotics is the foremost factor in the ever-increasing trend of bacterial antibiotic resistance1 . Streptococccus pneumoniae is a prevalent drug-resistant, pathogenic bacterium. It is the leading cause of pneumonia, sepsis and meningitis in children under the age of 52 . S. pneumoniae uses a high affinity ABC transporter (PsaBCA) to facilitate uptake of the essential trace metal manganese from its environment. The PsaBCA complex consists of three subunits: (1) substrate binding protein (PsaA); (2) trans-membrane domain (PsaC) and (3) a nucleotide binding domain (PsaB). It is known that PsaA acts to collect manganese ionsfrom the extracellular environment  3 and deliver them to the trans-membrane domain. Translocation of manganese across the cell membrane is powered by ATP hydrolysis at the nucleotide binding domain (PsaB).  The main aim for my honours year is to develop methods for the overexpression, purification and structural characterisation of the PsaB protein.  Progress toward that aim will be described.

  1. Pichichero ME (1999) Understanding antibiotic overuse for respiratory tract infections in children. Pediatrics 104: 1384-1388
  2. Jacobs MR, Good CE, Bajaksouzian S, Windau AR (2008) Emergence of Streptococcus pneumoniae serotypes 19A, 6C, and 22F and serogroup 15 in Cleveland, Ohio, in relation to introduction of the protein-conjugated pneumococcal vaccine. Clin Infect Dis 47: 1388-1395
  3. McAllister LJ, Tseng HJ, Ogunniyi AD, Jennings MP, McEwan AG, Paton JC (2004) Molecular analysis of the psa permease complex of Streptococcus pneumoniae. Mol Microbiol 53: 889-901