Cloning and sequence analysis of a cDNA encoding the beta-subunit of mouse beta-hexosaminidase

A cDNA encoding the prepro-beta-polypeptide of mouse beta-hexosaminidase (Hex) was isolated from a mouse lymphoblast cDNA library. The cDNA contains an open reading frame corresponding to a polypeptide of 536 amino acids which shows 74% homology with the human prepro-beta-polypeptide. An examination of the amino acid sequence identifies a putative signal peptide and five possible glycosylation sites, two of which are identical to the confirmed glycosylation sites of the human beta-chain. The amino acid sequence also shows a structurally similar though not identical site for internal cleavage responsible for the generation of mature beta a- and beta b-polypeptides.