Open AccessConformational analysis by CD and NMR spectroscopy of a peptide encompassing the amphipathic domain of YopD from Yersinia
Author(s) -
Tengel Tobias,
Sethson Ingmar,
Francis Matthew S.
Publication year - 2002
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1033.2002.03051.x
Subject(s) - yersinia pseudotuberculosis , peptide , chaperone (clinical) , peptide sequence , secretion , amphiphile , biology , chemistry , circular dichroism , nuclear magnetic resonance spectroscopy , biochemistry , biophysics , microbiology and biotechnology , stereochemistry , gene , virulence , medicine , organic chemistry , pathology , copolymer , polymer
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 YopD 278−300 , a peptide that strongly interacted with LcrH, was obtained by NMR methods. The structure is composed of a well‐defined amphipathic α helix ranging from Phe280 to Tyr291, followed by a type I β turn between residues Val292 and His295. The C‐terminal truncated peptides, YopD 278−292 and YopD 271−292 , lacked helical structure, implicating the β turn in helix stability. An interaction between YopD 278−300 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, YopD 278−292 , which confirms that the α helical structure of the YopD amphipathic domain is a critical binding region of LcrH.