Title:Structure of C-terminal Domain of Peptidyl-prolyl cis-trans Isomerase from Pseudomonas syringae pv. Tomato str. DC3000 at 1.6Å Resolution
Volume: 24
Issue: 6
Author(s): Yu Gao, Hong-mei Zhang, Pi-wu Wang*Mei Li*
Affiliation:
- College of Agronomy, Jilin Agricultural University. No.2888 Xincheng Street, Changchun, Jilin,China
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101,China
Keywords:
FKBP, PPIase, crystal structure, MIP, FK506, rapamycin.
Abstract: Background: Peptidyl-prolyl cis-trans isomerase (PPIase) accelerates the intrinsically
slow conversion between cis- and trans- configurations of proline, thus affecting backbone conformation
and altering the direction of peptide chains. PPIase from Pseudomonas syringae pv. Tomato
(PSPTO) DC3000 (PSPTO-PPIase) is considered to belong to the FKBP subfamily of PPIase.
Objective: To solve the high resolution structure of the PSPTO-PPIase, and to explore its potential
function in plants pathogen PSPTO DC3000.
Method: The PSPTO-PPIase was expressed in
E.coli and purified through ion exchange and size
exclusion chromatography. While only the C-terminal domain of PSPTO-PPIase was successfully
crystalized, and its structure was solved to 1.6 Å resolution by molecular replacement method.
Results: Structural comparison showed that PSPTO-PPIase adopts a similar overall fold with microphage
infectivity potentiators (MIPs), which also belong to the FKBP subfamily of PPIase. In
addition, the BIAcore result confirmed that PSPTO-PPIase can bind an immunosuppressive drug
FK506 as some other FKBP subfamily members do.
Conclusion: Our results suggested that PSPTO-PPIase may function in a similar manner to virulent
factor MIPs during pathogenesis. And the immunosuppressive drugs FK506 and rapamycin binding
to PSPTO-PPIase potentially interferes and inhibits the plant pathogen PSPTO DC3000. In addition,
the amino acids with short side chains in the fourth loop (L4) of PSPTO-PPIase may account
for its variable roles in the respective pathogen.
