IMPROVED 2-DEOXY-D-RIBOSE 5-PHOSPHATE ALDOLASES (DERAS) AND THE USES THEREOF

摘要

The invention relates to isolated mutants of enzymes from the group of 2-deoxy-D-ribose 5-phosphate aldolase wild-type enzymes having a productivity factor (as determined by a specific test) which is at least 10% higher than the productivity factor for the corresponding wild-type enzyme from which it is a mutant. The mutants have at least one amino acid substitution at one or more of the positions corresponding to K13, T19, Y49, N80, D84, A93, E127, A128, K146, K160, I166, A174, M185, K196, F200, and S239 in Escherichia coli K12 (EC 4.1.2.4) wild-type enzyme sequence, and/or a deletion of at least one amino acid at the positions corresponding to S258 and Y259 therein, optionally combined with, specific, C-terminal extension and/or N terminal extension. The invention also relates to screening processes to find 2-deoxy-D-ribose 5-phosphate aldolase enzymes (either as such or as mutants) having a productivity factor (as determined by said specific test, which forms an essential part of the screening) which is at least 10% higher than the reference value. Moreover, the invention relates to mutant enzymes obtained by the screening process, and to nucleic acids encoding such mutants, and to vectors and host cells comprising, respectively, such nucleic acids or mutants. Finally the invention relates to the use of such (preferably mutant) enzymes, nucleic acids, vectors and host cells in the production of, for instance, 6-chloro-2,4,6-trideoxy-D-erythrohexapyranoside.