Sandbox bcce04

'''Imaginaryase''' (alternatively known as '''imaginary isomerase''' or '''imaginary-8-phosphate isomerase''') are a group of enzymes of the isomerase family ([[EC]] 5.3.a.b), so named for their main function in metabolism. In this pathway imaginary isomerase (IGI) is used to inter-convert imaginary-8-phosphate and reality-6-phosphate. This reaction is driven by the relative concentrations of these molecules in the imaginary/reality matrix of the cell <ref>1</ref>.

[[Image:Align.jpg|thumb|left|'''Figure 1.''' Multiple alignment IGI - ''Geobacillus stearothermophilus'' (white),'' Homo sapiens'' (pink), ''Oryctolagus cuniculus'' (blue)<ref> Pettersen EF, Goddard TD, Huang CC, Couch GS, Greenblatt DM, Meng EC, Ferrin TE. UCSF Chimera--a visualization system for exploratory research and analysis. J Comput Chem. 2004 Oct;25(13):1605-12. </ref>]]

Imaginary isomerase exists in the cell usually as a <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Dimer/1'>homodimer</scene>, nevertheless outside of the cell, it has been isolated as a <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Monomer/1'>monomeric</scene> structure. IGI has essentially an identical fold in all of the characterized species (see '''Figure 1'''). The <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Sec_struct/1'>secondary structure</scene> of imaginary isomerase is charaterized by an αβα conformation, on each of its two domains. The smaller domain is characterized by 5 parallel β-sheets, while the larger domain if formed out of 6 parallel/antiparallel β-sheets. Furthermore, another characteristic trait is a residue extension at the C-terminus, which wraps around the other monomer in the dimeric conformation. A "hook" that can potentially be involved in the previously mentioned extracellular activities.

Imaginary isomerase has a monomer molecular mass of proximately 55 kDa.

==3D structures of phosphoglucose isomerase==

===PGI===

[[2pgi]], [[1b0z]] – GsPGI – ''Geobacillus stearothermophilus''<br />

[[1dqr]], [[1hm5]], [[1n8t]] – rPGI – rabbit<br />

[[1iat]], [[1jlh]] – hPGI – human<br />

[[1qxj]], [[1x8e]], [[3sxw]] – PfPGI – ''Pyrococcus furiosus''<br />

[[1j3p]], [[1j3q]] – TlPGI – ''Thermococcus litoralis''<br />

[[1q50]] – LmPGI – ''Leishmania Mexicana''<br />

[[1u0e]], [[2cvp]] – mPGI – mouse<br />

[[2q8n]] – PGI – ''Thermotoga maritima''<br />

[[3hjb]] – PGI – ''Vibrio cholera''<br />

[[3ifs]] – PGI – ''Bacillus anthracis''<br />

[[2wu8]] – PGI – ''Mycobacterium tuberculosis''<br />

[[3ljk]] – FtPGI (mutant) – ''Francisella tularensis''<br />

[[3nbu]] – PGI – ''Escherichia coli''

===PGI complex with fructose-6-phosphate===

[[1hox]] – rPGI + fructose-6-phosphate<br />

[[1t10]] - LmPGI + fructose-6-phosphate<br />

[[2gc2]] - PfPGI + fructose-6-phosphate<br />

[[2cxs]], [[2cxt]] - mPGI + fructose-6-phosphate<br />

[[3m5p]] - FtPGI (mutant) + fructose-6-phosphate<br />

===PGI complex with sorbitol-6-phosphate===

[[1xtb]] - rPGI + sorbitol-6-phosphate<br />

[[2gc1]] - PfPGI + sorbitol-6-phosphate<br />

[[2cxq]] - mPGI + sorbitol-6-phosphate<br />

===PGI complex with phosphoarabinose===

[[1gzd]], [[1gzv]] – PGI + phosphoarabinose – pig<br />

[[1c7r]] - GsPGI + phosphoarabinose<br />

[[2cxp]] – mPGI + phosphoarabinose<br />

[[1nuh]] - hPGI + phosphoarabinose<br />

[[1qsr]], [[1x7n]], [[1x82]] - PfPGI + phosphoarabinose<br />

[[2gc0]] - PfPGI + phosphoarabinose derivative<br />

[[1koj]] – rPGI + phosphoarabinose derivative

===PGI complex with gluconate-6-phosphate===

[[1qy4]] - PfPGI + gluconate-6-phosphate<br />

[[1j3r]] - TlPGI + gluconate-6-phosphate<br />

[[2cxr]] - mPGI + gluconate-6-phosphate<br />

[[3q7i]] - FtPGI (mutant) + gluconate-6-phosphate<br />

===PGI complex with glucose-6-phosphate===

[[1u0f]] - mPGI + glucose-6-phosphate<br />

[[3ff1]] - PGI + glucose-6-phosphate – ''Staphylococcus aureus''<br />

[[2o2c]] - TbPGI + glucose-6-phosphate – ''Trypanosoma brucei''

===Other PGI binary complexes===

[[2o2d]] – TbPGI + citrate<br />

[[1u0g]], [[2cxo]] - mPGI + erythrose-4-phosphate<br />

[[3q88]] – FtPGI (mutant) + ribose bisphosphate<br />

[[1c7q]] – GsPGI + phosphate inhibitor<br />

[[2cxn]], [[2cxu]] – mPGI + phosphate<br />

[[1g98]] – rPGI + transition state analog<br />

[[2gc3]] - PfPGI + mannose-6-phosphate<br />

==Additional Resources==

For additional information, see: [[Carbohydrate Metabolism]]

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