Molecular cloning and sequence analysis of cDNA encoding human cholesterol 7 alpha-hydroxylase

Area of Science:

• Biochemistry
• Molecular Biology
• Genetics

Background:

• Cholesterol 7 alpha-hydroxylase is a key enzyme in bile acid synthesis.
• Understanding its human form is crucial for metabolic research.

Purpose of the Study:

• To isolate and fully sequence the complementary DNA (cDNA) encoding human cholesterol 7 alpha-hydroxylase.
• To analyze the structural and functional characteristics of the human enzyme.

Main Methods:

• Utilized a rat P-450ch7 alpha cDNA insert as a probe for screening.
• Performed complete sequencing of the isolated human cDNA clone.

Main Results:

• Successfully isolated and sequenced a complete cDNA clone for human cholesterol 7 alpha-hydroxylase.
• The cDNA contains a 1512-base pair open reading frame encoding 504 amino acids.
• The deduced amino acid sequence exhibits 82% similarity to rat P-450ch7 alpha.
• Identified unique amino acid residues in conserved heme and steroid binding domains.

Conclusions:

• The human cholesterol 7 alpha-hydroxylase cDNA has been fully characterized.
• Structural similarities and unique residues suggest conserved and specific functions in steroidogenesis.