CPC C12N 9/0006 (2013.01) [C12N 9/0008 (2013.01); C12P 33/00 (2013.01); C12P 33/02 (2013.01); C12Y 101/01201 (2013.01)] | 8 Claims |
1. A nucleic acid molecule comprising a nucleotide sequence encoding a 7β-HSDH mutant, which catalyzes at least the stereospecific enzymatic reduction of a 7-ketosteroid to the corresponding 7-hydroxysteroid, wherein the mutant has at least 90% sequence identity to SEQ ID NO:2 and at least one mutation in the sequence motif VMVGRRE corresponding to positions 36 to 42 of SEQ ID NO:2, wherein the mutation is selected from the group consisting of:
a) the single mutation G39X1;
b) the single mutation R40X2;
c) the double mutation G39X1 R40X2
d) the double mutation R40X2 R41X3;
e) the double mutation G39X1 R41X3; and
f) the triple mutation G39X1 R40X2 R41X3; wherein each of X1, X2 and X3 can be the same or different and stands for mutated amino acid residues.
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