RefSeq NP_414975; from Ecocyc G6242: PpiD shows sequence similarity to peptidyl-prolyl cis-trans isomerases. PpiD has PPIase-independent chaperone activity. PpiD is predicted to contain an N-terminal transmembrane helix followed by three periplasmic domains. The second periplasmic domain (residues 264-357) is a parvulin-like domain which adopts a parvulin fold but does not catalyse cis-trans isomerisation of prolyl peptide bonds as is characteristic of parvulin proteins.
