The WLM (WSS1-like metalloprotease) domain is a globular domain related to the zincin-like superfamily of Zn-dependent peptidase. Since the WLM domain contains all known active site residues of zincins, it is predicted to be a catalytically active peptidase domain. The WLM domain is an eukaryotic domain represented in plants, fungi, Plasmodium, and kinetoplastids. By contrast, it is absent in animals, Cryptosporidium, and Microsporidia, suggesting that it has been lost on multiple occasions during the evolution of eukaryotes. The WLM domain is found either in stand-alone form or in association with other domains such as the RanBP2 zinc finger (see <PDOC50199>), the ubiquitin domain (see <PDOC00271>) or the PUB/PUG domain. The WLM domain could function as a specific de-SUMOylating domain of distinct protein complexes in the nucleus and the cytoplasm [1].

The WLM domain has been suggested to have a segregated α/β structure with eight helices and five strands [1].

Some proteins known to contain a WLM domain are listed below:

• Yeast WSS1 (Weak suppressor of Smt3p-1), a weak suppressor of the Ub- related protein SMT3.
• Arabidopsis thaliana putative uncharacterized protein At1g55915.
• Arabidopsis thaliana protein with similarity to zinc metalloproteinase.
• Schizosaccharomyces pombe ubiquitin/metalloprotease fusion protein SPCC1442.07c.
• Trypanosoma brucei ORF556.

The profile we developed covers the entire WLM domain.