Michael Glickman’s research program seeks to understand fundamental pathogenic strategies of mycobacteria and immunologic responses to mycobacteria. One major area of focus is the biosynthesis, pathogenetic role, and immunologic properties of the mycobacterial cell wall. We have defined the biosynthetic specificity and pathogenic role of mycolic acid cyclopropane synthases, a family of methyltransferases that modify M. tuberculosis cell wall mycolic acids with cyclopropane rings. In addition, we have discovered that regulated intramembrane proteolysis regulates the composition of the M. tuberculosis cell wall and is an important virulence determinant. In addition, my laboratory has demonstrated the existence, major molecular requirements, and characteristics of prokaryotic non-homologous end joining, a new pathway of prokaryotic double strand DNA break repair. These organisms are major worldwide pathogens and the ultimate goal of these studies is to validate new targets for antibiotic development and to understand the immunologic basis for their powerful adjuvant activity of mycobacteria.