<i>Mycobacterium tuberculosis</i> SatS is a chaperone for the SecA2 protein export pathway.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30604681.
- Also identified by DOI 10.7554/eLife.40063 and PMC identifier 6333443.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The SecA2 protein export system is critical for the virulence of <i>Mycobacterium tuberculosis</i>. However, the mechanism of this export pathway remains unclear. Through a screen for suppressors of a <i>secA2</i> mutant, we identified a new player in the mycobacterial SecA2 pathway that we named SatS for <u>S</u>ec<u>A</u>2 (<u>t</u>wo) <u>S</u>uppressor. In <i>M. tuberculosis</i>, 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 <i>M. tuberculosis</i> pathogenesis and in expanding our appreciation of the diversity among chaperones and protein export systems.
Medical subject headings
- Adenosine Triphosphatases
- Bacterial Proteins
- Macrophages
- Membrane Transport Proteins
- Mycobacterium tuberculosis