Dimeric glycerol dehydratases
The invention concerns a method for preparing 1,3-propanediol from a carbon-containing substance, said method comprising a step which consists in culturing a recombinant micro-organism not producing coenzyme B12 in the absence of coenzyme B12 or one of its precursors. The invention also concerns a nucleic acid coding for a glycerol dehydratase whereof the catalytic activity is independent of the presence of coenzyme B12 or one of its precursors and a nucleic acid coding for a 1,3-propanol dehydrogenase intervening in the synthesis of 1,3-propanediol. The invention further concerns recombinant vectors and host cells comprising said nucleic acids and the polypeptides coded by the latter.
1. A recombinant dimeric glycerol dehydratase comprising: (a) a first polypeptide having at least 90% amino acid identity with the amino acid sequence of SEQ ID NO: 6, and (b) a second polypeptide having at least 95% amino acid identity with the amino acid sequence of SEQ ID NO: 7.
2. The recombinant dimeric glycerol dehydratase according to claim 1 , wherein the first polypeptide is encoded by a first polynucleotide having at least 95% nucleotide identity with the polynucleotide of sequence SEQ ID NO: 1.
3. The recombinant dimeric glycerol dehydratase according to claim 1 , wherein the second polypeptide is encoded by a second polynucleotide having at least 95% nucleotide identity with the polynucleotide of sequence SEQ ID NO: 2.
4. A recombinant dimeric glycerol dehydratase comprising (a) a first polypeptide consisting of the amino acid sequence of SEQ ID NO: 6, and (b) a second polypeptide consisting of the amino acid sequence of SEQ ID NO: 7.
5. The recombinant dimeric glycerol dehydratase according to claim 4 , wherein the first polypeptide is encoded by a first polynucleotide of sequence SEQ ID NO: 1.
6. The recombinant dimeric glycerol dehydratase according to claim 4 , wherein the second polypeptide is encoded by a second polynucleotide of sequence SEQ ID NO: 2.