Structural highlights 
  Function 
SAMP2_HALVD Protein modifier that is covalently attached to lysine residues of substrate proteins. The tagging system is termed SAMPylation. It is not known whether it is implicated in the targeting of proteins to the proteasome for degradation. Is able to form polymeric chains with itself at Lys-58, similar to ubiquitin and other ubiquitin-like proteins.