Members of this family are found in proteasome regulatory subunits, eukaryotic initiation factor 3 (eIF3) subunits and regulators of transcription factors. This family is also known as the MPN domain [3] and PAD-1-like domain [4], JABP1 domain [5] or JAMM domain [7]. These are metalloenzymes that function as the ubiquitin isopeptidase/ deubiquitinase in the ubiquitin-based signalling and protein turnover pathways in eukaryotes [7]. Versions of the domain in prokaryotic cognates of the ubiquitin-modification pathway are shown to have a similar role, and the archael protein from Haloferax volcanii is found to cleave ubiquitin-like small archaeal modifier proteins (SAMP1/2) from protein conjugates [8,9].

1: Homologues of 26S proteasome subunits are regulators of transcription and translation. Aravind L, Ponting CP; Protein Sci 1998;7:1250-1254. PMID:9605331

2: Conservation and diversity in the structure of translation initiation factor EIF3 from humans and yeast. Hershey JW, Asano K, Naranda T, Vornlocher HP, Hanachi P, Merrick WC; Biochimie 1996;78:903-907. PMID:9150866

3: The PCI domain: a common theme in three multiprotein complexes. Hofmann K, Bucher P; Trends Biochem Sci 1998;23:204-205. PMID:9644972

4: Eukaryotic signalling domain homologues in archaea and bacteria. Ancient ancestry and horizontal gene transfer. Ponting CP, Aravind L, Schultz J, Bork P, Koonin EV; J Mol Biol 1999;289:729-745. PMID:10369758

5: A global census of fission yeast deubiquitinating enzyme localization and interaction networks reveals distinct compartmentalization profiles and overlapping functions in endocytosis and polarity. Kouranti I, McLean JR, Feoktistova A, Liang P, Johnson AE, Roberts-Galbraith RH, Gould KL; PLoS Biol. 2010; [Epub ahead of print] PMID:20838651

6: Biogenesis and function of multivesicular bodies. Piper RC, Katzmann DJ; Annu Rev Cell Dev Biol. 2007;23:519-547. PMID:17506697

7: Role of Rpn11 metalloprotease in deubiquitination and degradation by the 26S proteasome. Verma R, Aravind L, Oania R, McDonald WH, Yates JR 3rd, Koonin EV, Deshaies RJ; Science. 2002;298:611-615. PMID:12183636

8: The prokaryotic antecedents of the ubiquitin-signaling system and the early evolution of ubiquitin-like beta-grasp domains. Iyer LM, Burroughs AM, Aravind L; Genome Biol. 2006;7:R60. PMID:16859499

9: Archaeal JAB1/MPN/MOV34 metalloenzyme (HvJAMM1) cleaves ubiquitin-like small archaeal modifier proteins (SAMPs) from protein-conjugates. Hepowit NL, Uthandi S, Miranda HV, Toniutti M, Prunetti L, Olivarez O, De Vera IM, Fanucci GE, Chen S, Maupin-Furlow JA; Mol Microbiol. 2012;86:971-987. PMID:22970855