View source for Triosephosphate isomerase

{{Protbox
   |Name=Triosephosphate isomerase 1
   |Photo=Beta-barrel.png
   |Caption=The structure of human TPI {{PDB|1WYI}}
   |width=200
   |AltSymbols=TIM
   |HGNCid=12009
   |Symbol=TPI1
   |Chromosome=12
   |Arm=p
   |Band=13
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  |Accession_numbers=
   |OMIM=190450
   |EntrezGene=7167
   |RefSeq=NM_000365
   |UniProt=P60174 
  |PDB = 
   |ECnumber=5.3.1.1 
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==Overview==

'''Triose-phosphate isomerase''' (TPI or TIM), is an [[enzyme]] ({{EC number|5.3.1.1}}) that [[catalyst|catalyzes]] the reversible interconversion of the [[triose]] phosphate [[isomer]]s [[dihydroxyacetone phosphate]] and D-[[glyceraldehyde 3-phosphate]].

{{Enzymatic Reaction
|foward_enzyme=[[triose phosphate isomerase]]
|reverse_enzyme=[[triose phosphate isomerase]]
|substrate=[[Dihydroxyacetone phosphate]]
|product=<small>D</small>-[[glyceraldehyde 3-phosphate]]
|reaction_direction_(foward/reversible/reverse)=reversible
|minor_foward_substrate(s)=
|minor_foward_product(s)=
|minor_reverse_substrate(s)=
|minor_reverse_product(s)=
|substrate_image=glycerone-phosphate_wpmp.png
|product_image=D-glyceraldehyde-3-phosphate_wpmp.png
}}
{{KEGG compound|C00111}}{{KEGG enzyme|5.3.1.1}}{{KEGG compound|C00118}}

[[Triose phosphate isomerase]] ('''TPI''') plays an important role in [[glycolysis]] and is essential for efficient energy production. TPI has been found in nearly every organism searched for the enzyme, including animals such as [[mammals]] and [[insect]]s as well as in [[fungi]], [[plant]]s and [[bacteria]]. However, some bacteria that do not perform glycolysis, like [[Ureaplasma|ureaplasmas]], lack TPI.

In humans, deficiencies in TPI are associated with a progressive, severe neurological disorder called [[Triose Phosphate Isomerase deficiency]].

Triose phosphate isomerase is a massively efficient enzyme, performing the reaction billions of times faster than it would occur naturally in solution. The reaction is so efficient it is limited only by the rate the substrate can [[diffuse]] into the enzyme's active site.

[[Image:TPI1 structure.png|thumb|right|300px|Side view of triose phosphate isomerase.]]
==Structure==
Triose phosphate isomerase is a [[dimer]] of identical [[subunit]]s, each of which is made up of about 250 [[amino acid]] residues. The three-dimensional structure of a subunit contains eight [[alpha helix|&alpha;-helices]] (<span style="color: turquoise; font-weight: bold;">blue</span> and <span style="color: red; font-weight: bold;">red</span>) on the outside and eight parallel [[beta sheet|&beta;-strands]] on the inside (<span style="color: BlueViolet; font-weight: bold;">violet</span> and <span style="color: Gold; font-weight: bold;">yellow</span>). This structural motif is called an &alpha;&beta;-barrel, or a [[TIM_barrel|TIM-barrel]], and is by far the most commonly observed [[Protein folding|protein fold]]. The [[active site]] of this enzyme is in the center of the barrel. A [[glutamic acid]] residue is involved in the [[catalytic mechanism]].  The sequence around the active site residue is conserved in all known triose phosphate isomerases.

<br style="clear: both;" />

==See also==
*  [[TIM barrel]]
* [[Triose Phosphate Isomerase deficiency]]

==References==
http://pdbdev.sdsc.edu:48346/pdb/molecules/pdb50_6.html

[[Category:EC 5.3.1]]

{{glycolysis}}
{{Intramolecular oxidoreductases}}
{{Glycolysis enzymes}}

[[de:Triosephosphatisomerase]]
[[it:Trioso fosfato isomerasi]]
[[pt:Triose-fosfato isomerase]]
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