Avtor/Urednik | Anderluh, Gregor; Goekce, Isa; Lakey, Jeremy H | |
Naslov | A natively unfolded toxin domain uses its receptor as a folding template | |
Tip | članek | |
Vir | J Biol Chem | |
Vol. in št. | Letnik 279, št. 21 | |
Leto izdaje | 2004 | |
Obseg | str. 22002-9 | |
Jezik | eng | |
Abstrakt | Natively unfolded proteins range from molten globules to disordered coils. They are abundant in eukaryotic genomes and commonly involved in molecular interactions. The essential N-terminal translocation domains of colicin toxins from Escherichia coli are disordered bacterial proteins that bind at least one protein of the Tol or Ton family. The colicin N translocation domain (CoIN-(1-90)), whieh binds to the C-terminal domain of ToIA (ToIA-(296421)), shows a disordered far-UV CD spectrum, no near-UV CD signal, and non-cooperative thermal unfolding. As expected, ToIA-(296-421) displays both secondary structure in far-LTV CD and tertiary structure in near-UV CD. Furthermore it shows a cooperative unfolding transition at 65 °C. CD spectra of the 1:1 eomplex show both increased secondary structure and colicin N-specific near-L1V CD signals. A new cooperative thermal transition at 35 °C is followed by the unchanged unfolding behavior of ToIA-(296-421). Fluorescence and surface plasmon resonance confirm that the new unfolding transition accompanies dissociation of CoIN-(1-90). Hence upon binding the disordered structure of CoIN-(1-90) converts to a cooperatively folded domain without altering the TolA-(296-421) structure. | |
Deskriptorji | ESCHERICHIA COLI COLICINS PROTEIN STRUCTURE, SECONDARY PROTEIN STRUCTURE, TERTIARY PROTEIN BINDING PROTEIN FOLDING SPECTROPHOTOMETRY, ULTRAVIOLET SPECTROMETRY, FLUORESCENCE CHROMATOGRAPHY, GEL |