Alignment of human PSMA subunits 1–8. Protein sequences of the eight proteasome PSMA subunits were aligned using Clustal W. , identical residue in all seven subunits; :, conserved amino acids with strongly similar properties; ., conservation between residues of weakly similar properties. Naturally occurring variants are highlighted with grey boxes. Alternatively spliced regions are underlined. Amino acid residue numbers are shown on the left and right of each sequence and the UniProt accession number and gene name of each sequence are shown to the right of each sequence. PSMA8 (PSMA7L) is found only in mammalian testis and is a spermatid/sperm-specific subunit [33].
