Publications

Conserved residues are critical for Haloferax volcanii archaeosortase catalytic activity: Implications for convergent evolution of the catalytic mechanisms of non‐homologous sortases from archaea and bacteria.

Faculty Author(s): Stoltzfus, Jonathan D.
Student Author(s): -
Department: BIOL
Publication: Molecular Microbiology
Year: 2018
Abstract: Summary: Proper protein anchoring is key to the biogenesis of prokaryotic cell surfaces, dynamic, resilient structures that play crucial roles in various cell processes. A novel surface protein anchoring mechanism in Haloferax volcanii depends upon the peptidase archaeosortase A (ArtA) processing C‐termini of substrates containing C‐terminal tripartite structures and anchoring mature substrates to the cell membrane via intercalation of lipid‐modified C‐terminal amino acid residues. While this membrane protein lacks clear homology to soluble sortase transpeptidases of Gram‐positive bacteria, which also process C‐termini of substrates whose C‐terminal tripartite structures resemble those of ArtA substrates, archaeosortases do contain conserved cysteine, arginine and arginine/histidine/asparagine residues, reminiscent of His‐Cys‐Arg residues of sortase catalytic sites. The study presented here shows that ArtAWT‐GFP expressed in trans complements ΔartA growth and motility phenotypes, while alanine substitution mutants, Cys173 (C173A), Arg214 (R214A) or Arg253 (R253A), and the serine substitution mutant for Cys173 (C173S), fail to complement these phenotypes. Consistent with sortase active site replacement mutants, ArtAC173A‐GFP, ArtAC173S‐GFP and ArtAR214A‐GFP cannot process substrates, while replacement of the third residue, ArtAR253A‐GFP retains some processing activity. These findings support the view that similarities between certain aspects of the structures and functions of the sortases and archaeosortases are the result of convergent evolution. [ABSTRACT FROM AUTHOR] Copyright of Molecular Microbiology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Link: Conserved residues are critical for Haloferax volcanii archaeosortase catalytic activity: Implications for convergent evolution of the catalytic mechanisms of non‐homologous sortases from archaea and bacteria.