Generation of Mycobacterium tuberculosis deletion mutants of the ESX-1 locus

The ESX-1, type VII, secretion system represents the major virulence determinant of Mycobacterium tuberculosis. The ESX-1 cluster comprises approximately twenty genes and encodes a specialized secretion apparatus, which releases effectors into the extracellular milieu. Disruption in the ESX-1 locus often results in attenuation of the pathogen. In order to study the function of the ESX-1 components, we generated knock-out mutants by deleting individual genes in the ESX-1 locus.