NiFe-hydrogenases having an improved resistance to dioxygen, process for obtaining them and their applications

摘要

The invention relates to [NiFe] -hydrogenases having an improved resistance to dioxygen, said [NiFe]-hydrogenases may be obtained by: - providing an initial polynucleotide comprising a sequence encoding a large subunit of a [NiFe] -hydro genase, said large subunit comprising the following peptide motifs: • L1 : RGXE, wherein X = L, I, F, V or M • L2: [R/K]X1C[G/R]X2C, wherein Xi is any amino acid residue, X2 = L, V, I or M; L1 and L2 being separated by 16 any amino acid residues; • L3: X1X2X3X4X5X6X7X8X9X10X11X12[D/S/E], wherein X1 = D, S, N or E, X2 = H, D, S, N or L, X5 = H, S, A, Q or W, X6 = F, T, Y or G, X9 = L, F, M or Y, the other Xn being any amino acid residue; • L4: D[P/I/S]CX1X2CX3X4[H/R], wherein X2 = A.S.V.G or T, X1, X3 and X4 are any amino acid residue • and optionally comprising a motif LO: R[I/V/A]EG[H/D/A]. - modifying said initial polynucleotide in order to substitute at least one of the residues X2 of motif L2 andZor X4 of motif L3 andZor X9 of motif L3 of said large subunit by a methionine.