Protein Domain : PPE family, C-terminal IPR022171

Type	Domain
Description	The human pathogen Mycobacterium tuberculosis harbours a large number of genes that encode proteins whose N-termini contain the characteristic motifs Pro-Glu (PE) or Pro-Pro-Glu (PPE). A subgroup of the PE proteins contains polymorphic GC-rich sequences (PGRS), while a subgroup of the PPE proteins contains major polymorphic tandem repeats (MPTR). The function of most of these proteins remains unknown [ ]. However, the PE_PGRS proteins from Mycobacterium marinum are secreted by components of the ESX-5 system that belongs to the recently defined type VII secretion systems []. It has also been reported that the PE_PGRS family of proteins contains multiple calcium-binding and glycine-rich sequence motifs GGXGXD/NXUX. This sequence repeat constitutes a calcium-binding parallel β-roll or parallel β-helix structure and is found in RTX toxins secreted by many Gram-negative bacteria []. This domain family is found in bacteria, and is approximately 90 amino acids in length. The family is found in association with . There is a conserved SVP sequence motif. There is a single completely conserved residue W that may be functionally important. The proteins in this family are PE/PPE proteins implicated in immunostimulation and virulence.
Short Name	PPE_C