Disease relevance of tpiA

• By gene dosage effects, transformed cells of E. coli C600 with these pBR322 hybrid plasmids showed 7- and 16-fold increases in the specific activities of phosphofructokinase and triosephosphate isomerase, respectively, over the specific activities in C600 [1].
• The transcriptional organization of the Corynebacterium glutamicum gap-pgk-tpi-ppc gene cluster, encoding glyceraldehyde-3-phosphate dehydrogenase, 3-phosphoglycerate kinase, triosephosphate isomerase, and phosphoenolpyruvate carboxylase, was investigated by Northern (RNA) blot and primer extension analyses [2].
• Phosphoglycerate kinase and triosephosphate isomerase from the hyperthermophilic bacterium Thermotoga maritima form a covalent bifunctional enzyme complex [3].
• Sequence of the triosephosphate isomerase-encoding gene isolated from the thermophile Bacillus stearothermophilus [4].
• Triosephosphate isomerase (EC 5.3.1.1) from Lactococcus lactis was purified to electrophoretic homogeneity [5].

High impact information on tpiA

• Here, we provide evidence that a nonsense codon at position 1, 2 or 10 reduces the abundance of nucleus-associated TPI mRNA to an average of only 84% of normal because translation reinitiates at the methionine codon at position 14 [6].
• These and related findings lend credence to the concept that the nonsense-mediated reduction in the half-life of nucleus-associated TPI mRNA involves cytoplasmic ribosomes [6].
• A comparison of the amino acid sequence of both the PGK and the TIM parts of the fusion protein with those of known PGKs and TIMs reveals high similarity to the corresponding enzymes from different procaryotic and eucaryotic organisms [3].
• The corresponding pgk and tpi genes are part of the apparent gap operon of T. maritima [3].
• Active site of triosephosphate isomerase: in vitro mutagenesis and characterization of an altered enzyme [7].

Chemical compound and disease context of tpiA

• An E. coli TIM crystal grown in the absence of 2PG, diffracting to 2.6 A resolution, was later obtained by application of the technique of macro-seeding using a seed crystal grown from a mother liquor without 2PG [8].
• This is consistent with the hypothesis that PV4-8 TPI increased arsenate resistance in E. coli by directly or indirectly functioning as an arsenate reductase [9].
• Partial NMR assignments and secondary structure mapping of the isolated alpha subunit of Escherichia coli tryptophan synthase, a 29-kD TIM barrel protein [10].
• Four proteins (triosephosphate isomerase, alpha galactosidase, Hsp90, and glucosamine 6-phosphate synthase) constitute the majority of E. coli proteins that bind and potentially may coelute during chromatography [11].

Biological context of tpiA

• The amino acid sequences of the three enzymes show up to 62% (GAPDH), 48% (PGK), and 44% (TPI) identity in comparison with respective enzymes from other organisms [12].
• The three additional genes found on the 4.5-kb DNA fragment encoded for proteins involved in aromatic amino acid biosynthesis (aroA), DNA bending (himD), and carbohydrate metabolism (tpiA) [13].
• Sequence analysis of the chromosomal region flanking the Tn5 within KW239 revealed strong similarities to a number of known Escherichia coli gene products and DNA sequences: the nusA operon, including the complete initiator tRNA(Met) gene, metY; a tRNA(Leu) gene; the tpiA gene product; and the MrsA protein [14].
• We have determined the sequence requirements for the N-terminal protein hinge of the active-site lid of triosephosphate isomerase [15].
• Stepwise improvements in catalytic effectiveness: independence and interdependence in combinations of point mutations of a sluggish triosephosphate isomerase [16].

Associations of tpiA with chemical compounds

• Triosephosphate isomerase: removal of a putatively electrophilic histidine residue results in a subtle change in catalytic mechanism [17].
• Each of the second-site mutations increases the specific catalytic activity of a triosephosphate isomerase in which the catalytic base, glutamate-165, has been changed to aspartate [16].
• The essential catalytic base at the active site of the glycolytic enzyme triosephosphate isomerase is the carboxylate group of Glu-165, which directly abstracts either the 1-pro-R proton of dihydroxyacetone phosphate or the 2-proton of (R)-glyceraldehyde 3-phosphate to yield the cis-enediol intermediate [18].
• Reaction energetics of a mutant triosephosphate isomerase in which the active-site glutamate has been changed to aspartate [18].
• We have replaced asparagine residues at the subunit interface of yeast triosephosphate isomerase (TIM) using site-directed mutagenesis in order to elucidate the effects of substitutions on the catalytic activity and conformational stability of the enzyme [19].

Other interactions of tpiA

• The secG gene, downstream tpiA, does not make part of this polygenic organization, being actively transcribed as a monocistronic mRNA during transition to the stationary phase of growth [20].

Analytical, diagnostic and therapeutic context of tpiA

• Protein engineering on trypanosomal triosephosphate isomerase (TIM) converted this oligomeric enzyme into a stable, monomeric protein that is enzymatically active [21].
• Subunit interface of triosephosphate isomerase: site-directed mutagenesis and characterization of the altered enzyme [19].
• Sedimentation equilibrium ultracentrifugation runs showed that RE-TIM is a monomer in solution [22].
• Dissection of the gene of the bifunctional PGK-TIM fusion protein from the hyperthermophilic bacterium Thermotoga maritima: design and characterization of the separate triosephosphate isomerase [23].
• This sequence, and that of a region conserved in all known bacterial triosephosphate isomerases, was used to design oligonucleotide primers for the synthesis of a lactococcal tpi probe by PCR [5].

References