| 摘要 |
This invention relates to the production of 7-dehydrocholesterol, 25-hydroxy-7-dehydrocholesterol, and 25-hydroxy ergosterol in yeast such as Saccharomyces cerevisiae. It also relates to various enzymes catalyzing the reduction of the double bond at position 24 of lanosterol, dimethyl zymosterol, methyl zymosterol, zymosterol, cholesta-7, 24-dienol, or cholesta-5,7,24-trienol; or the hydroxylation at position 25 of ergosterol, 7-dehydrocholesterol, cholesta-8-enol, and cholesta-7-enol. It also relates to various nucleic acids encoding cholesterol C25-hydroxylases and sterol Δ24-reductases and their use to produce and hydroxylate 7-dehydrocholesterol or ergosterol. It also relates to the yeast strains so produced, and methods of making these sterols that include the steps of cultivaton a transformed yeast cell, and harvesting the resulting sterol(s). |
| 主权项 |
1. Yeast comprising a nucleic acid encoding cholesterol C25-hydroxylase which has been codon-optimized for expression in yeast and encodes a cholesterol C25 hydroxylase with an amino acid sequence that is at least 90% identical with an amino acid sequence selected from the group consisting of SEQ ID NO: 6, SEQ ID NO: 9, SEQ ID NO: 18, SEQ ID NO: 21, SEQ ID NO: 24, and SEQ ID NO: 29;
wherein the yeast possesses no active Erg5p and Erg6p enzymes, and the yeast also expresses a sterol Δ24-reductase. |
