title: The N-terminal, dehydrogenase/cyclohydrolase domain of yeast cytoplasmic trifunctional C1-tetrahydrofolate synthase requires the C-terminal, synthetase domain for the catalytic activity in vitro.
abstract: The yeast ADE3(1-333) gene which encodes a truncated protein containing the N-terminal 5,10-methylene-tetrahydrofolate (THF) dehydrogenase (D)/5,10-methyl-THF cyclohydrolase (C) domain of cytoplasmic trifunctional C1-THF synthase is able to complement all the phenotypes associated with ade3 mutations in vivo. However, expression of the ADE3(1-333) gene in an ade3 strain does not retain any D activity in vitro. Expression in a yeast ade3 strain of the ADE3(1-333) fused to the Escherichia coli lacZ gene or to the yeast SER2 gene allows detection of D and C activities in vitro. These results indicate that the N-terminal D/C domain of C1-THF synthase requires the C-terminal 10-formyl-THF synthetase domain for stable catalytic activity in vitro.
mesh_terms: D000483:Alleles; D000619:Aminohydrolases / Q000737:chemistry* / Q000378:metabolism; D005574:Formate-Tetrahydrofolate Ligase / Q000737:chemistry* / Q000378:metabolism; D005816:Genetic Complementation Test; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP) / Q000737:chemistry* / Q000378:metabolism; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism; D010641:Phenotype; D011994:Recombinant Proteins; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D017384:Sequence Deletion; D013329:Structure-Activity Relationship
chemical_list: D009097:Multienzyme Complexes; D011994:Recombinant Proteins; C021836:formyl-methenyl-methylenetetrahydrofolate synthetase; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP); D000619:Aminohydrolases; D005574:Formate-Tetrahydrofolate Ligase