Table 2. Functional assignments of the structural components involved in ESX-1 secretion pathway.

Component name	Known function (from literature)	Probable function (obtained from present study)	Function derived from
Multimeric assembly of secretory proteins
Rv3868	ATPase	Initiation of the assembly of multiprotein complexes	Domain analysis, 3D fold analysis, literature
Recognition of secretory proteins and motor activity
Rv3870, Rv3871	Delivery of ESAT-6/CFP-10 pair to the secretion machinery	ATPase motor to recruit the secretory proteins to the inner membrane pore (Rv3877) and facilitate translocation	Domain analysis, 3D fold analysis, literature
Inner membrane translocation
Rv3877	Pore forming protein located in the inner membrane	Inner membrane pore. Regulates secretion of proteins through its interaction with MycP1	Domain analysis, motif analysis, literature
Proteolytic processing and secretion regulation at the periplasm-like space
Rv3883c (MycP1)	Protease which cleaves EspB (Rv3881c)	Cleaves the ubiquitin-like domain of Rv3877, thereby opening the gate and initiating translocation of secretory proteins	Motif analysis, literature
Mycomembrane translocation
Rv3869	Membrane protein of unknown function	Component required for the formation of the mycomembrane translocation machinery	Domain analysis, glycosylation site prediction, protein-protein association prediction, literature
Rv3882c	Membrane protein predicted to face periplasm	Component required for the formation of the mycomembrane translocation machinery	Protein-protein association prediction, literature
MCE1 proteins (Mce1B, Mce1C, Mce1F, Rv0177)	Unknown	Component required for the formation of the mycomembrane translocation machinery	Phylogenetic profile analysis, protein-protein association prediction, literature