Conformational analysis by CD and NMR spectroscopy of a peptide encompassing the amphipathic domain of YopD from Yersinia.Tengel, T., Sethson, I., Francis, M.S.
(2002) Eur.J.Biochem. 269: 3659-3668
- PubMed: 12153562
- PubMed Abstract:
To establish an infection, Yersinia pseudotuberculosis utilizes a plasmid-encoded type III secretion machine that permits the translocation of several anti-host factors into the cytosol of target eukaryotic cells. Secreted YopD is essential for this ...
To establish an infection, Yersinia pseudotuberculosis utilizes a plasmid-encoded type III secretion machine that permits the translocation of several anti-host factors into the cytosol of target eukaryotic cells. Secreted YopD is essential for this process. Pre-secretory stabilization of YopD is mediated by an interaction with its cognate chaperone, LcrH. YopD possesses LcrH binding domains located in the N-terminus and in a predicted amphipathic domain located near the C-terminus. This latter domain is also critical for Yersinia virulence. In this study, we designed synthetic peptides encompassing the C-terminal amphipathic domain of YopD. A solution structure of YopD278-300, a peptide that strongly interacted with LcrH, was obtained by NMR methods. The structure is composed of a well-defined amphipathic alpha helix ranging from Phe280 to Tyr291, followed by a type I beta turn between residues Val292 and His295. The C-terminal truncated peptides, YopD278-292 and YopD271-292, lacked helical structure, implicating the beta turn in helix stability. An interaction between YopD278-300 and its cognate chaperone, LcrH, was observed by NMR through line-broadening effects and chemical shift differences between the free peptide and the peptide-LcrH complex. These effects were not observed for the unstructured peptide, YopD278-292, which confirms that the alpha helical structure of the YopD amphipathic domain is a critical binding region of LcrH.
Department of Organic Chemistry, Umeå University, Umeå, Sweden.