Coding

Part:BBa_K4700000

Designed by: Thomas James Alexander   Group: iGEM23_BOKU-Vienna   (2023-10-07)


7-dehydrocholesterol reductase (DHCR7)

Part type - Enzyme CDS - Class: Oxidoreductase (catalyzes e- transfer) - Coenzymes: (NADP+ / NADPH) or (NAD+ / NADH)

Other Names: Delta7-Sterol Reductase; 7-DHC reductase; Δ7-reductase; EC: 1.3.1.21

Function: Reduction/Oxidation of double bond between the 7th and 8th carbon of sterane ring structure, on the B ring, of the sterol molecules suspended as in the cell membrane that serve as the substrate of our process. (e.x. Cholesterol [animals], Campesterol [plants], Ergosterol [yeasts])

In our anabolic process to ferment steroid hormones from simple carbon, this enzyme reduces the sterane ring to remove the double bond between C7/C8. This is an important step in engineering suitable substrates for the Cytochrome 450ssc (Side-Chain-Cleaving) enzymes, in the step immediately following, CYP11A.

Ergosterol, the native yeast sterol, has an IUPAC name of Ergosta-5,7,22-trien-3-ol. Compared to Cholesterol, which has an IUPAC name that can be written as Cholest-5-en-3-ol, we see the major relevant difference is the presence of the C7 double bond. (The C22 double bond can be modified by yeast native Δ22-reductase aka ERG4)

The action of DHCR7 creates a suitable substrate to begin steroid synthesis.

Reactions Catalyzed:

7-Dehydrocholesterol + NADH + H+ <=> Cholesterol + NAD+ (In Animals)

Ergosta-5,7-dienol + NADPH <=> Ergosta-5-enol + NADP+ (In Yeast, with A. thaliana enzyme from Duport 1997)

Ergosta-5,7,22-trienol + NADPH <=> Ergosta-5,22-dienol + NADP+ (In Yeast, with A. thaliana enzyme from Duport 1997)

Organism of Origin:

     -BOKU-Vienna 2023: Danio rerio (Zebra Fish)
     -UCSC 2018: Arabidopsis thaliana - (Originally described in Duport et. al 1997)

Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal NgoMIV site found at 412
    Illegal NgoMIV site found at 1015
  • 1000
    COMPATIBLE WITH RFC[1000]


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