Download MendeleyThe Structure of a Burkholderia Pseudomallei Immunophilin-Inhibitor Complex Reveals New Approaches to Antimicrobial Development
Norville, I.H., O'Shea, K., Sarkar-Tyson, M., Zheng, S., Titball, R.W., Varani, G., Harmer, N.J.(2011) Biochem J 437: 413
- PubMed: 21574961
- DOI: https://doi.org/10.1042/BJ20110345
- Primary Citation of Related Structures:
2KE0, 2KO7, 2Y78 - PubMed Abstract:
Mips (macrophage infectivity potentiators) are a subset of immunophilins associated with virulence in a range of micro-organisms. These proteins possess peptidylprolyl isomerase activity and are inhibited by drugs including rapamycin and tacrolimus. We determined the structure of the Mip homologue [BpML1 (Burkholderia pseudomallei Mip-like protein 1)] from the human pathogen and biowarfare threat B. pseudomallei by NMR and X-ray crystallography. The crystal structure suggests that key catalytic residues in the BpML1 active site have unexpected conformational flexibility consistent with a role in catalysis. The structure further revealed BpML1 binding to a helical peptide, in a manner resembling the physiological interaction of human TGFβRI (transforming growth factor β receptor I) with the human immunophilin FKBP12 (FK506-binding protein 12). Furthermore, the structure of BpML1 bound to the class inhibitor cycloheximide N-ethylethanoate showed that this inhibitor mimics such a helical peptide, in contrast with the extended prolyl-peptide mimicking shown by inhibitors such as tacrolimus. We suggest that Mips, and potentially other bacterial immunophilins, participate in protein-protein interactions in addition to their peptidylprolyl isomerase activity, and that some roles of Mip proteins in virulence are independent of their peptidylprolyl isomerase activity.
Organizational Affiliation:
School of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK.
