Triosephosphate isomerase (EC:5.3.1.1) (TIM) [1] is the glycolytic enzyme that catalyses the reversible interconversion of glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. TIM plays an important role in several metabolic pathways and is essential for efficient energy production, present in eukaryotes and prokaryotes. TIM is a dimer of identical subunits, each of which is made up of about 250 amino-acid residues. A glutamic acid residue is involved in the catalytic mechanism [2,3]. The tertiary structure of TIM has eight beta/alpha motifs folded into a barrel structure [4]. The sequence around the active site residue is perfectly conserved in all known TIM's. Deficiencies in TIM are associated with haemolytic anaemia coupled with a progressive, severe neurological disorder [5].

1: Structure of yeast triosephosphate isomerase at 1.9-A resolution. Lolis E, Alber T, Davenport RC, Rose D, Hartman FC, Petsko GA; Biochemistry. 1990;29:6609-6618. PMID:2204417

2: Enzyme catalysis: not different, just better. Knowles JR; Nature. 1991;350:121-124. PMID:2005961

3: Optimal alignment for enzymatic proton transfer: structure of the Michaelis complex of triosephosphate isomerase at 1.2-A resolution. Jogl G, Rozovsky S, McDermott AE, Tong L; Proc Natl Acad Sci U S A. 2003;100:50-55. PMID:12509510

4: One fold with many functions: the evolutionary relationships between TIM barrel families based on their sequences, structures and functions. Nagano N, Orengo CA, Thornton JM; J Mol Biol. 2002;321:741-765. PMID:12206759

5: Triosephosphate isomerase deficiency: a neurodegenerative misfolding disease. Olah J, Orosz F, Keseru GM, Kovari Z, Kovacs J, Hollan S, Ovadi J; Biochem Soc Trans. 2002;30:30-38. PMID:12023819