Model of Type VII Secretion System Figure 3. Workflow showing various methodologies used for functional annotation of components of Type VII secretion system in M. Tuberculosis. doi:10.1371/journal.pone.0027980.g003 Prediction of protein-protein association Probable protein-protein associations were predicted using the MtbPPI tool (http://www.cdfd.org.in/MtbPPI/). The tool con- tains a comprehensive protein linkage network of M. tuberculosis H37Rv, predicted using Support Vector Machine with parameters derived from various genomic context methods (phylogenetic profile, gene distance, etc.) and microarray expression data. The network captures all known interacting pairs in M. tuberculosis. Thus, the association among the proteins involved in ESX-1 secretion can be verified using this network. PLoS ONE | www.plosone.org 10 November 2011 | Volume 6 | Issue 11 | e27980