5.3.3.2 C113S inactive 727623 5.3.3.2 C113S/114S inactive 727623 5.3.3.2 C114S inactive 727623 5.3.3.2 C67A inactive mutant enzyme 650979 5.3.3.2 D216A mutation of highly conserved residue 704638 5.3.3.2 E116Q inactive mutant enzyme 651594 5.3.3.2 E116Q the ratio of maximal velocity to turnover number is 0.09%% of that of the wild-type enzyme 650979 5.3.3.2 E13R/R235E the mutant and the wild-type enzyme show similar Vmax values, while the Km of E13R/R235E is smaller than that of the wild type. The mutant is in the tetrameric state even at a concentration where the wild-type enzyme dominantly forms an octamer 719740 5.3.3.2 E161A mutation of highly conserved residue 704638 5.3.3.2 E169/171Q inactive 727623 5.3.3.2 E169Q inactive 727623 5.3.3.2 E171Q inactive 727623 5.3.3.2 E194A mutation of highly conserved residue 704638 5.3.3.2 E229A mutation of highly conserved residue 704638 5.3.3.2 E87Q inactive mutant enzyme 651594 5.3.3.2 E87Q the ratio of maximal velocity to turnover number is 0.07% of that of the wild-type enzyme 650979 5.3.3.2 H11A mutation of highly conserved residue 704638 5.3.3.2 H155A mutation of highly conserved residue 704638 5.3.3.2 K193A mutation of highly conserved residue 704638 5.3.3.2 K55A the ratio of maximal velocity to turnover number is 66% of that of the wild-type enzyme 650979 5.3.3.2 K55R the ratio of maximal velocity to turnover number is 28% of that of the wild-type enzyme 650979 5.3.3.2 K8A mutation of highly conserved residue 704638 5.3.3.2 L141H the mutation enhances the enzyme activity 1.1fold 748596 5.3.3.2 L141H/W256C the mutations enhance the enzyme activity 1.65fold 748596 5.3.3.2 L141H/Y195F the mutations enhance the enzyme activity 2.03fold 748596 5.3.3.2 L141H/Y195F/W256C the mutation enhances the enzyme activity 3.13fold 748596 5.3.3.2 additional information functional expression in engineered Escherichia coli restores the carotenoid pathway 692027 5.3.3.2 additional information gene IPI can accelerate the accumulation of beta-carotene in Escherichia coli transformants 691400 5.3.3.2 additional information isoform IDI2 can complete isomerase function in an idi1-deficient yeast strain 680882 5.3.3.2 additional information mutants lacking isoform idi1 activity have no major morphological or chemical differences from the wild-type. Mutants lacking both isoforms idi1 and idi2 are non-viable 694638 5.3.3.2 additional information mutants lacking isoform idi2 activity have no major morphological or chemical differences from the wild-type except for flowers with fused sepals and underdeveloped petals. Mutants lacking both isoforms idi1 and idi2 are non-viable 694638 5.3.3.2 additional information mutants lacking isoform ipi1 activity are phenotypically normal. Mutants lacking the activities of both isoforms ipi1 and ipi2 exhibit dwarfism and male sterility under long-day conditions, and decreased pigmentation under continuous light. The sterol and ubiquinone levels of the double mutant are less than 50% of wild-type level. The male-sterile phenotype is complemented by squalene 694654 5.3.3.2 additional information mutants lacking isoform ipi2 activity are phenotypically normal. Mutants lacking the activities of both isoforms ipi1 and ipi2 exhibit dwarfism and male sterility under long-day conditions, and decreased pigmentation under continuous light. The sterol and ubiquinone levels of the double mutant are less than 50% of wild-type level. The male-sterile phenotype is complemented by squalene 694654 5.3.3.2 additional information recombinant expression in Escherichia coli. Gene IBI can take the role of Arabidopsis thaliana IDI to produce the orange beta-carotene 691183 5.3.3.2 N125A mutation of highly conserved residue 704638 5.3.3.2 N157A mutation of highly conserved residue 704638 5.3.3.2 N37A the mutant is a monomeric but active enzyme with by 20°C lowered melting temperature and reduced binding affinities of FMN (40fold) and a minimal effect on the kcat value compared to the wild type enzyme 747106 5.3.3.2 Q154N active site mutant 715286 5.3.3.2 Q160A mutation of highly conserved residue 704638 5.3.3.2 Q160E 10-fold decrease in kcat/Km 728667 5.3.3.2 Q160E the mutant shows a 10fold decrease in kcat/Km 728667 5.3.3.2 Q160H 23-fold decrease in kcat/Km 728667 5.3.3.2 Q160H the mutant shows a 23fold decrease in kcat/Km 728667 5.3.3.2 Q160K 130-fold decrease in kcat/Km 728667 5.3.3.2 Q160K the mutant shows a 130fold decrease in kcat/Km 728667 5.3.3.2 Q160L 28-fold decrease in kcat/Km 728667 5.3.3.2 Q160L the mutant shows a 28fold decrease in kcat/Km 728667 5.3.3.2 Q160N 150-fold decrease in kcat, kcat/Km decreases 66-fold 728667 5.3.3.2 Q160N the mutant shows a 150fold decrease in kcat, although kcat/Km only decreases 66fold 728667 5.3.3.2 R232A mutation of highly conserved residue 704638 5.3.3.2 R51K the ratio of maximal velocity to turnover number is 4.2% of that of the wild-type enzyme 650979 5.3.3.2 R7A mutation of highly conserved residue 704638 5.3.3.2 R83K the ratio of maximal velocity to turnover number is 104% of that of the wild-type enzyme 650979 5.3.3.2 S96A mutation of highly conserved residue 704638 5.3.3.2 T68A mutation of highly conserved residue 704638 5.3.3.2 W161F the ratio of maximal velocity to turnover number is 0.8% of that of the wild-type enzyme 650979 5.3.3.2 W216F 10% activity compared to the wild type enzyme 727623 5.3.3.2 W256C the mutation enhances the enzyme activity 0.47fold 748596 5.3.3.2 Y104A 0.1% of wild-type activity. Crystallization data. The M2+ metal-binding site is absent in the structure, but Mg2+ is still present and bound to C67, E87, and four water molecules 680660 5.3.3.2 Y104F 0.1% of wild-type activity. Crystallization data. General fold of enzyme is similar to wild-type 680660 5.3.3.2 Y105F 115% activity compared to the wild type enzyme 727623 5.3.3.2 Y195F the mutation enhances the enzyme activity 0.71fold 748596 5.3.3.2 Y195F/W256C the mutations enhance the enzyme activity 1.14fold 748596