PLoS ONE (Jan 2011)

A minimum of three motifs is essential for optimal binding of pseudomurein cell wall-binding domain of Methanothermobacter thermautotrophicus.

  • Ganesh Ram R Visweswaran,
  • Bauke W Dijkstra,
  • Jan Kok

DOI
https://doi.org/10.1371/journal.pone.0021582
Journal volume & issue
Vol. 6, no. 6
p. e21582

Abstract

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We have biochemically and functionally characterized the pseudomurein cell wall-binding (PMB) domain that is present at the C-terminus of the Surface (S)-layer protein MTH719 from Methanothermobacter thermautotrophicus. Chemical denaturation of the protein with guanidinium hydrochloride occurred at 3.8 M. A PMB-GFP fusion protein not only binds to intact pseudomurein of methanogenic archaea, but also to spheroplasts of lysozyme-treated bacterial cells. This binding is pH dependent. At least two of the three motifs that are present in the domain are necessary for binding. Limited proteolysis revealed a possible cleavage site in the spacing sequence between motifs 1 and 2 of the PMB domain, indicating that the motif region itself is protected from proteases.