Structural basis of interaction between dimeric cyclophilin 1 and Myb1 transcription factor in Trichomonas vaginalis

Sci Rep. 2018 Apr 3;8(1):5410. doi: 10.1038/s41598-018-23821-5.

Abstract

Cyclophilin 1 (TvCyP1), a cyclophilin type peptidyl-prolyl isomerase present in the human parasite Trichomonas vaginalis, interacts with Myb1 and assists in its nuclear translocation. Myb1 regulates the expression of ap65-1 gene that encodes for a disease causing cytoadherence enzyme. Here, we determined the crystal structures of TvCyP1 and its complex with the minimum TvCyP1-binding sequence of Myb1 (Myb1104-111), where TvCyP1 formed a homodimer, unlike other single domain cyclophilins. In the complex structure, one Myb1104-111 peptide was bound to each TvCyP1 protomer, with G106-P107 and Y105 fitting well into the active site and auxiliary S2 pocket, respectively. NMR data further showed that TvCyP1 can catalyze the cis/trans isomerization of P107 in Myb1104-111. Interestingly, in the well-folded Myb1 protein (Myb135-141), the minimum binding sequence adopted a different conformation from that of unstructured Myb1104-111 peptide, that could make P107 binding to the active site of TvCyP1 difficult. However, NMR studies showed that similar to Myb1104-111 peptide, Myb135-141 also interacted with the active site of TvCyP1 and the dynamics of the Myb135-141 residues near P107 was reduced upon interaction. Together, the structure of TvCyP1 and detailed structural insights on TvCyP1-Myb1 interaction provided here could pave the way for newer drugs to treat drug-resistant strains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Cyclophilins / chemistry*
  • Cyclophilins / metabolism*
  • Models, Molecular
  • Peptidylprolyl Isomerase / metabolism
  • Protein Binding
  • Protein Domains
  • Protein Multimerization*
  • Protein Stability
  • Protein Structure, Quaternary
  • Protozoan Proteins / chemistry*
  • Protozoan Proteins / metabolism*
  • Transcription Factors / metabolism*
  • Trichomonas vaginalis*

Substances

  • Protozoan Proteins
  • Transcription Factors
  • Cyclophilins
  • Peptidylprolyl Isomerase