Mouse cytochrome P3-450: complete cDNA and amino acid sequence

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Cytochrome P450 enzymes are crucial for metabolizing xenobiotics and endogenous compounds.
• Understanding the genetic basis of P450s is vital for drug development and toxicology.

Purpose of the Study:

• To isolate and characterize the full-length cDNA of mouse cytochrome P3-450.
• To investigate the evolutionary relationship of mouse P3-450 with other P450 proteins.
• To identify key amino acid residues involved in the enzyme's active site.

Main Methods:

• Isolation and sequencing of a full-length mouse cytochrome P3-450 cDNA clone using the Okayama-Berg vector.
• Sequence homology analysis comparing mouse P3-450 with rat P-450b, P-450e, and P-450d proteins.
• Identification of conserved regions and potential active site residues.

Main Results:

• A 1,894-nucleotide cDNA clone of mouse cytochrome P3-450 was successfully sequenced.
• Significant sequence homology was observed between mouse P3-450 and rat P-450b/e, suggesting a common ancestral gene.
• High identity was found between the N- and C-termini of mouse P3-450 and rat P-450d.
• Cysteine 456 was identified as a likely thiolate ligand to the heme iron in the active site.

Conclusions:

• Mouse P3-450 shares evolutionary origins with rat P-450b and P-450e.
• The structural data supports the role of cysteine 456 in the catalytic activity of mouse P3-450.