Structure of the rat gene encoding cholesterol 7 alpha-hydroxylase.
Cholesterol 7 alpha-hydroxylase (7 alpha-hydroxylase) is a microsomal cytochrome P-450 that catalyzes the first and rate-limiting step in bile acid biosynthesis, the major catabolic pathway in cholesterol homeostasis. The gene encoding the rat 7 alpha-hydroxylase has been isolated and characterized. Southern blotting experiments demonstrated that the gene is present in a single copy in the rat genome. DNA sequence analysis showed that the 7 alpha-hydroxylase gene is unique among the characterized cytochrome P-450s in that it contains only six exons. Nuclease S1 and primer-extension mapping experiments positioned the 5'-ends of the 7 alpha-hydroxylase mRNA approximately 20-25 nucleotides downstream of a consensus TATAAA sequence. RNA blotting experiments demonstrated the presence of multiple 7 alpha-hydroxylase mRNAs that differ in the lengths of their 3'-untranslated regions.
Jelinek
D F
DF
Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75235.
Russell
D W
DW
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002790:Cholesterol 7-alpha-Hydroxylase / Q000235:genetics*; D004247:DNA / Q000737:chemistry; D005091:Exons; D007438:Introns; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000737:chemistry; D051381:Rats / Q000235:genetics*; D014158:Transcription, Genetic
D012333:RNA, Messenger; D004247:DNA; D002790:Cholesterol 7-alpha-Hydroxylase