Triosephosphate isomerase, active site <p>Triosephosphate isomerase (<db_xref db="EC" dbkey="5.3.1.1"/>) (TIM) [<cite idref="PUB00000326"/>] 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. It is present ineukaryotes as well as in 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 [<cite idref="PUB00004091"/>, <cite idref="PUB00029041"/>].</p><p>The tertiary structure of TIM has eight beta/alpha motifs folded into a barrel structure. The TIM barrel fold occurs ubiquitously and is found in numerous other enzymes that can be involved in energy metabolism, macromolecule metabolism, or small molecule metabolism [<cite idref="PUB00027646"/>].</p><p>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 [<cite idref="PUB00014239"/>].</p><p> This entry represents a triosephosphate isomerase conserved site. </p>