X‐ray structure of peptidyl‐prolyl cis–trans isomerase A from Mycobacterium tuberculosis

Abstract

Peptidyl-prolyl cis-trans isomerases (EC 5.2.1.8) catalyse the interconversion of cis and trans peptide bonds and are therefore considered to be important for protein folding. They are also thought to participate in processes such as signalling, cell surface recognition, chaperoning and heatshock response. Here we report the soluble expression of recombinant Mycobacterium tuberculosis peptidyl-prolyl cis-trans isomerase PpiA in Escherichia coli, together with an investigation of its structure and biochemical properties. The protein was shown to be active in a spectrophotometric assay, with an estimated k cat /K m of 2.0 · 10 6 M )1 AEs )1 . The X-ray structure of PpiA was solved by molecular replacement, and refined to a resolution of 2.6 Å with R and R free values of 21.3% and 22.9%, respectively. Comparisons to known structures show that the PpiA represents a slight variation on the peptidyl-prolyl cis-trans isomerase fold, previously not represented in the Protein Data Bank. Inspection of the active site suggests that specificity for substrates and cyclosporin A will be similar to that found for most other enzymes of this structural family. Comparison to the sequence of the second M. tuberculosis enzyme, PpiB, suggests that binding of peptide substrates as well as cyclosporin A may differ in that case.

Assessment of Live Candidate Vaccines for Paratuberculosis in Animal Models and Macrophages

“…This enzyme is considered important for protein folding and thought to participate in cell signaling, cell surface recognition, chaperoning, and heat shock responses (19).…”

Cytosolic Proteome Profiling of Aminoglycosides Resistant Mycobacterium tuberculosis Clinical Isolates Using MALDI-TOF/MS

“…Our study assumes that over expression of this protein regulate the transcription of mycobacteria even in low transcriptional state or dormant state. Rv0009 (Probable iron-regulated peptidyl prolyl cis–trans isomerase A) is probably involved in cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerated protein folding (Henriksson et al, 2004). Recently Lata et al reported the higher expression of Rv0009 in ofloxacin and moxifloxacin induced M. tuberculosis (Lata et al, 2015a).…”

Mycobacterium tuberculosis Cyclophilin A Uses Novel Signal Sequence for Secretion and Mimics Eukaryotic Cyclophilins for Interaction with Host Protein Repertoire

“…Structures of the selected sequences were obtained from PDB database, as described previously [13], [23] and sequence alignments were done in CLUSTAL X. Individual or overlapped cyclophilin 3-D structures were viewed in Chimera (http://www.cgl.ucsf.edu/chimera/) [37].…”

“…Individual or overlapped cyclophilin 3-D structures were viewed in Chimera (http://www.cgl.ucsf.edu/chimera/) [37]. The PDB ids used for structural analyses are as follows: 1W74 ( M. tuberculosis PpiA), 1LOP ( E. coli PpiA), 2CPL (Human PPIA), 2A2N (Human PPWD1), 2OK3 (Human PPIL3), 2ESL (PPIC) [13], [23]. Specific regions of interest are shown in Figure 3.…”

“…The former has been shown to be present in culture filtrates in several studies [10], [20] and is reported to be upregulated in intraphagosomal niche during infection [21]. Although independent groups have partly characterized PpiA with respect to cyclosporin binding or structural moiety [22], [23], no thorough investigation has been made to understand the phylogeny, secretion mechanism and interactome of PpiA.…”