Disease relevance of folA

• Conditional dihydrofolate reductase deficiency due to transposon Tn5tac1 insertion downstream from the folA gene in Escherichia coli [1].
• New details of NADPH binding to Lactobacillus casei dihydrofolate reductase have become visible as a result of crystallographic refinement to an R factor of 0.152 at 1.7 A resolution [2].
• Cyclic dihydrofolate reductase displayed improved in vitro thermostability, and pseudostellarin F production was readily apparent in vivo through its inhibition of melanin production catalyzed by recombinant Streptomyces antibioticus tyrosinase [3].
• Neisseria gonorrhoeae dihydrofolate reductase undergoes a time-dependent, irreversible inactivation by 2,4-diamino-5-[3,5-dimethoxy-4-(p-bromoacetamidophenoxy)benzyl] pyrimidine [4].
• The complete amino acid sequence of the mutant dihydrofolate reductase from Streptococcus faecium var [5].

High impact information on folA

• A kinetic analysis has shown that the reaction catalyzed by dihydrofolate reductase is optimized with respect to product flux, which in turn is predetermined by the active-site hydrophobic surface [6].
• Neutron diffraction studies of Escherichia coli dihydrofolate reductase complexed with methotrexate [7].
• Impact of distal mutations on the network of coupled motions correlated to hydride transfer in dihydrofolate reductase [8].
• Single-molecule and transient kinetics investigation of the interaction of dihydrofolate reductase with NADPH and dihydrofolate [9].
• Analysis of the energetic couplings provides access to the thermodynamic domain structure in dihydrofolate reductase as well as the susceptibility of the different regions of the protein to both small-scale (e.g., point mutations) and large-scale perturbations (e. g., binding ligand) [10].

Chemical compound and disease context of folA

• Binding of F-MTX to E. coli folA DHFR was inhibitable as by both MTX and TMP, whereas MTX but not TMP blocked binding of F-MTX to recombinant mouse DHFR [11].
• Dihydrofolate reductase: the amino acid sequence of the enzyme from a methotrexate-resistant mutant of Escherichia coli [12].
• The crystal structure of dihydrofolate reductase (EC 1.5.1.3) from Escherichia coli has been solved as the binary complex with NADP+ (the holoenzyme) and as the ternary complex with NADP+ and folate [13].
• Crystal structures of Escherichia coli dihydrofolate reductase: the NADP+ holoenzyme and the folate.NADP+ ternary complex. Substrate binding and a model for the transition state [13].
• Crystal structure of unliganded Escherichia coli dihydrofolate reductase. Ligand-induced conformational changes and cooperativity in binding [14].

Biological context of folA

• Effect of a single amino acid substitution on Escherichia coli dihydrofolate reductase catalysis and ligand binding [15].
• The active site loop of DHFR was labeled with a fluorescence quencher, QSY35, at amino acid position 17, and the fluorescent probe, Alexa555, at amino acid 37, by introducing cysteines at these sites with site-specific mutagenesis [16].
• Conformation coupled enzyme catalysis: single-molecule and transient kinetics investigation of dihydrofolate reductase [16].
• 2) Plasmid pLC1437a coded for dihydrofolate reductase in vitro [17].
• Plasmid pLC1437a was shown by two criteria to carry the structural gene for dihydrofolate reductase: 1) A partial diploid containing plasmid pLC1437a produced a kinetically-recognizable dihydrofolate reductase that was not present in the parent haploid strain [17].

Anatomical context of folA

• The presecretory protein preprocecropinA (which comprises 64 amino acid residues) as well as a synthetic hybrid between preprocecropinA and dihydrofolate reductase (which comprises 252 amino acid residues) are processed by and transported into mammalian microsomes [18].
• A fusion between the N-terminal 15 amino acid residues of beta-subunit and the mouse cytosolic protein dihydrofolate reductase (DHFR) was transcribed and translated in vitro and found to be transported into isolated yeast mitochondria [19].
• Two novel analogues of aminopterin with a single fluorine substitution in the 2' (compound 8) or in the 3' (compound 9) position of the p-aminobenzoyl group were synthesized and evaluated as inhibitors of dihydrofolate reductase from two bacterial species and from human HeLa cells [20].
• Translation of this recombinant mRNA in the Escherichia coli cell-free system resulted in the synthesis of DHFR, which was two orders of magnitude higher than that in the case of translation of the control DHFR mRNA [21].
• Purified DNA from Chinese hamster ovary (CHO) cells was reacted in vitro with the active metabolites N-acetoxy-IQ or N-acetoxy-MelQx, and the adduct levels in the 5' dihydrofolate reductase (DHFR) gene and downstream region were quantitated by Southern hybridization [22].

Associations of folA with chemical compounds

• The increase in SHMT activity was sufficient to correct the glycine auxotrophy of strains lacking folA [23].
• The coding region of the dihydrofolate reductase gene, folA, was replaced with a kanamycin resistance determinant [24].
• We show that a folA mutant that overexpressed dihydrofolate reductase because of a C to T promoter mutation, adapted very slowly when transferred from rich medium at 37 degrees C to glucose minimal medium at 42 degrees C. It adapted more rapidly when serine and threonine were added [25].
• R67 dihydrofolate reductase (R67 DHFR) is a novel protein encoded by an R-plasmid that confers resistance to the antibiotic, trimethoprim [26].
• R67 dihydrofolate reductase (R67 DHFR) catalyzes the transfer of a hydride ion from NADPH to dihydrofolate, generating tetrahydrofolate [27].

Other interactions of folA

• Nucleotide sequence of the thymidylate synthase B and dihydrofolate reductase genes contained in one Bacillus subtilis operon [28].

Analytical, diagnostic and therapeutic context of folA

• The refolded DHFR was purified by methotrexate-Sepharose affinity chromatography to give the homogeneous enzyme [29].
• Immunoprecipitation and chemical cross-linking experiments revealed that SCE70-DHFR is targeted to the same complex as SCE70 in the chloroplast envelope [30].
• The purified DHFR migrates as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with apparent mass of approximately 30 kDa, and gel filtration showed that the protein is a monomer [29].
• The complete amino acid sequence of dihydrofolate reductase from an amethopterin-resistant strain of Lactobacillus casei has been determined by sequence analysis of peptides produced by cleavage with cyanogen bromide, trypsin, staphylococcal protease, and myxobacter protease [31].
• The stopped-flow circular dichroism (CD) measurements show that the CD spectra at the early stages of folding are similar among the mutants and the wild-type DHFR, indicating that the presence of the complete set of folding elements is sufficient to preserve the early folding events [32].

References