Mycobacterium tuberculosis SatS is a chaperone for the SecA2 protein export pathway. Academic Article uri icon


  • The SecA2 protein export system is critical for the virulence of Mycobacterium tuberculosis. However, the mechanism of this export pathway remains unclear. Through a screen for suppressors of a secA2 mutant, we identified a new player in the mycobacterial SecA2 pathway that we named SatS for SecA2 (two) Suppressor. In M. tuberculosis, SatS is required for the export of a subset of SecA2 substrates and for growth in macrophages. We further identify a role for SatS as a protein export chaperone. SatS exhibits multiple properties of a chaperone, including the ability to bind to and protect substrates from aggregation. Our structural studies of SatS reveal a distinct combination of a new fold and hydrophobic grooves resembling preprotein-binding sites of the SecB chaperone. These results are significant in better defining a molecular pathway for M. tuberculosis pathogenesis and in expanding our appreciation of the diversity among chaperones and protein export systems.

published proceedings

  • Elife

altmetric score

  • 8.1

author list (cited authors)

  • Miller, B. K., Hughes, R., Ligon, L. S., Rigel, N. W., Malik, S., Anjuwon-Foster, B. R., Sacchettini, J. C., & Braunstein, M.

citation count

  • 8

complete list of authors

  • Miller, Brittany K||Hughes, Ryan||Ligon, Lauren S||Rigel, Nathan W||Malik, Seidu||Anjuwon-Foster, Brandon R||Sacchettini, James C||Braunstein, Miriam

publication date

  • January 2019


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