Disruption of the S41 Peptidase Gene in Mycoplasma mycoides capri Impacts Proteome Profile, H2O2 Production, and Sensitivity to Heat Shock

Members of the Mycoplasma mycoides cluster are among the most virulent of the mycoplasmas, causing worldwide economically significant diseases of cattle and goats. A distinguishing phenotype among the members of the cluster is the ability to degrade casein. The MMCAP2_0241 gene, an S41 peptidase, confers the proteolytic phenotype in Mycoplasma mycoides subsp. capri GM12. In order to determine the impact of disruption of the gene, we used differential proteome profiling to compare the M. mycoides subsp. capri wild type with a mutant lacking the proteolytic phenotype. Disruption of MMCAP2_0241 resulted in altered phenotypes reminiscent of M. mycoides subsp. mycoides SC and had significant impacts on the proteome profile of the microbe. The mutant exhibited increased production of hydrogen peroxide, decreased lactate dehydrogenase activity, and increased sensitivity to heat shock.