Archaeal ubiquitin-like SAMP3 is isopeptide-linked to proteins via a UbaA-dependent mechanism.

ABSTRACT: SAMP1 and SAMP2 are ubiquitin-like proteins that function as protein modifiers and are required for the production of sulfur-containing biomolecules in the archaeon Haloferax volcanii. Here we report a novel small archaeal modifier protein (named SAMP3) with a β-grasp fold and C-terminal diglycine motif characteristic of ubiquitin that is functional in protein conjugation in Hfx. volcanii. SAMP3 conjugates were dependent on the ubiquitin-activating E1 enzyme homolog of archaea (UbaA) for synthesis and were cleaved by the JAMM/MPN+ domain metalloprotease HvJAMM1. Twenty-three proteins (28 lysine residues) were found to be isopeptide-linked to the C-terminal carboxylate of SAMP3, and 331 proteins were reproducibly found associated with SAMP3 in a UbaA-dependent manner based on tandem mass sp

SUBMITTER: Miranda HV 

PROVIDER: S-EPMC3879616 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature