4.1.1.18	A225C/T302C	site-directed mutagenesis, due to high flexibility at the pyridoxal 5'-phosphate (PLP) binding site, use of the enzyme for cadaverine production requires continuous supplement of large amounts of PLP. In order to develop an LDC enzyme from Selenomonas ruminantium (SrLDC) with an enhanced affinity for PLP, an internal disulfide bond between Ala225 and Thr302 residues is introduced with a desire to retain the PLP binding site in a closed conformation. The SrLDCA225C/T302C mutant shows bound PLP, and exhibits 3fold enhanced PLP affinity compared with the wild-type SrLDC. The mutant also exhibits a dramatically enhanced LDC activity and cadaverine conversion particularly under no or low PLP concentrations. Introduction of the disulfide bond renders mutant SrLDC more resistant to high pH and temperature. The formation of the introduced disulfide bond and the maintenance of the PLP binding site in the closed conformation are confirmed by determination of the crystal structure of the mutant. Mutant structure determination and analysis, overview. The mutant shows increased affinity for pyridoxal 5'-phosphate and increased activity compared to wild-type	749101	
4.1.1.18	A44V/G45T/V46P	the ratio of activity with L-Orn to activity with L-Lys is 1.0, compared to 0.69 for the wild-type enzyme	654984	
4.1.1.18	A44V/G45T/V46P	the ratio of turnover number to Km-value obtained with L-Orn relative to that obtained with L-Lys as substrate is 2.0, compared to 0.83 for the wild-type enzyme	655829	
4.1.1.18	A44V/G45T/V46P/P54D	the ratio of turnover number to Km-value obtained with L-Orn relative to that obtained with L-Lys as substrate is 3.8, compared to 0.83 for the wild-type enzyme	655829	
4.1.1.18	A44V/G45T/V46P/P54D/S322A	the ratio of turnover number to Km-value obtained with L-Orn relative to that obtained with L-Lys as substrate is 58, compared to 0.83 for the wild-type enzyme	655829	
4.1.1.18	A44V/G45T/V46P/P54D/S322T/I326L	the ratio of turnover number to Km-value obtained with L-Orn relative to that obtained with L-Lys as substrate is 13, compared to 0.83 for the wild-type enzyme	655829	
4.1.1.18	A52C	the ratio of activity with L-Orn to activity with L-Lys is 1.2, compared to 0.69 for the wild-type enzyme	654984	
4.1.1.18	A52C	the ratio of turnover number to Km-value obtained with L-Orn relative to that obtained with L-Lys as substrate is 1.0, compared to 0.83 for the wild-type enzyme	655829	
4.1.1.18	A52C/P54D	the ratio of activity with L-Orn to activity with L-Lys is 2.6, compared to 0.69 for the wild-type enzyme	654984	
4.1.1.18	A52C/P54D	the ratio of turnover number to Km-value obtained with L-Orn relative to that obtained with L-Lys as substrate is 1.6, compared to 0.83 for the wild-type enzyme	655829