PE-PPE

Family: PE-PPE

Block: X

Parent Family: No family

Comment

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). This domain is found C-terminal to the PE (IPR000084) and PPE (IPR000030) domains. Only a few of these domain are associated with alpha/beta hydrolases. The secondary structure of this domain is predicted to be a mixture of alpha helices and beta strands, and recently demonstrated to be alpha/beta hydrolase: see Sultana et al. This protein domain is close to cutinase. The membrane-associated acyltransferase Chp1 (myctu-Rv3822) accepts a synthetic diacyl sulfolipid and transfers an acyl group regioselectively from one donor substrate molecule to a second acceptor molecule in two successive reactions to yield a tetraacylated product. The rv1184c locus encodes Chp2, an acyltransferase in polyacyltrehalose lipid biosynthesis. In fact this domain is found in many unrelated folds only a few are alpha/beta hydrolases (Sultana 2016)