The membrane localization domains of two distinct bacterial toxins form a 4-helix-bundle in solution

Protein Sci. 2017 Mar;26(3):497-504. doi: 10.1002/pro.3097. Epub 2017 Feb 14.

Abstract

Membrane localization domain (MLD) was first proposed for a 4-helix-bundle motif in the crystal structure of the C1 domain of Pasteurella multocida toxin (PMT). This structure motif is also found in the crystal structures of several clostridial glycosylating toxins (TcdA, TcdB, TcsL, and TcnA). The Ras/Rap1-specific endopeptidase (RRSP) module of the multifunctional autoprocessing repeats-in-toxins (MARTX) toxin produced by Vibrio vulnificus has sequence homology to the C1-C2 domains of PMT, including a putative MLD. We have determined the solution structure for the MLDs in PMT and in RRSP using solution state NMR. We conclude that the MLDs in these two toxins assume a 4-helix-bundle structure in solution.

Keywords: 4-helix-bundle; Pasteurella multocida; Vibrio vulnificus; bacterial toxin; membrane localization domains; solution NMR spectroscopy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Bacterial Toxins / chemistry*
  • Bacterial Toxins / genetics
  • Bacterial Toxins / metabolism
  • Cell Membrane / chemistry*
  • Cell Membrane / genetics
  • Cell Membrane / metabolism
  • Pasteurella multocida / chemistry*
  • Pasteurella multocida / genetics
  • Pasteurella multocida / metabolism
  • Protein Domains
  • Protein Structure, Secondary
  • Sequence Homology, Amino Acid
  • Vibrio vulnificus / chemistry*
  • Vibrio vulnificus / genetics
  • Vibrio vulnificus / metabolism

Substances

  • Bacterial Proteins
  • Bacterial Toxins
  • Pasteurella multocida toxin