Mov34/MPN/PAD-1 family: UPF0172 family of unknown function includes neighbor of COX4 (Noc4p)This family includes Noc4p (neighbor of COX4; neighbor of Cytochrome c Oxidase 4; nucleolar complex associated 4 homolog) which belongs to the family of unknown function, UPF0172, with MPN/JAMM-like domains. Proteins in this family are homologs of the NOC4 gene which is conserved in eukaryotic members including human, dog, mouse, rat, chicken, zebrafish, fruit fly, mosquito, S.pombe, K.lactis, E.gossypii, M.grisea, N.crassa, A.thaliana, and rice. NOC4 highly expressed in the pancreas and moderately in liver, heart, lung, kidney, brain, skeletal muscle, and placenta. This nucleolar protein forms a complex with Nop14p that mediates maturation and nuclear export of 40S ribosomal subunits. This family of eukaryotic MPN-like domains lacks the key residues that coordinate a metal ion and therefore does not show catalytic isopeptidase activity.