THE ISOLATION AND CHARACTERIZATION OF THE HUMAN CYTOCHROME B(5) GENE

From a series of lambda and cosmid libraries, we isolated DNA sequence s corresponding to the complete coding region for the human cytochrome b(5) (CYB5) gene. The overall gene organization was the same as the b ovine and rabbit CYB5 genes. One cosmid clone containing exon I plus t he 5' flanking region was extensively characterized. From this clone w e obtained 2000 bp of 5' flanking sequence, containing several distinc tive GC rich regions, potential trans-acting factor binding sites and a 74 bp direct repeat. A series of deletion constructs were made in th e pGL2 luciferase vector and then used to transfect HepG2 and K562 cel ls. The data obtained suggest the presence of two promoters and one si lencer region in the analyzed 5' sequence. (C) 1995 Academic Press, In c.