Characterization of the human HEXB gene encoding lysosomal beta-hexosaminidase.

The lysosomal enzyme beta-hexosaminidase A contains alpha- and beta-subunits that are encoded by the HEXA and HEXB genes, respectively. The human HEXB gene has been isolated and characterized. It is 45 kb long and is split into 14 exons. Of the 13 introns, 12 interrupt the coding sequences at homologous positions in the HEXA and HEXB genes. The 5' flanking region contains the functional HEXB gene promoter. While a fine-structure analysis has yet to be done, we note that the sequence is GC rich and has several GC boxes and one CAAT box. There are also sequences related or identical to a progesterone response element and an AP-1 binding motif.