Ribose-5-phosphate isomerase: Difference between revisions
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<StructureSection load='3enw' size="400" color="" spin="on" Scene= caption='Ribose-5-phosphate isomerase A dimer complex with ribulose-5-phosphate, [[3enw]]' > | |||
==Introduction== | |||
'''Ribose 5-phosphate isomerase''' (Rpi) is a highly conserved protein that acts as an enzyme in both eukaryotic and prokaryotic metabolic pathways<ref name="rpi">PMID:12517338</ref>. Specifically, Rpi catalyzes the reaction that converts <scene name='Sandbox_Reserved_305/Ligand/1'> ribose-5-phosphate </scene> (R5P) to ribulose-5-phosphate (Ru5P). Rpi exists as two distinct protein forms known as RpiA and RpiB, both of which catalyze the same reaction, and most organisms express one or both of these enzymes. | '''Ribose 5-phosphate isomerase''' (Rpi) is a highly conserved protein that acts as an enzyme in both eukaryotic and prokaryotic metabolic pathways<ref name="rpi">PMID:12517338</ref>. Specifically, Rpi catalyzes the reaction that converts <scene name='Sandbox_Reserved_305/Ligand/1'> ribose-5-phosphate </scene> (R5P) to ribulose-5-phosphate (Ru5P). Rpi exists as two distinct protein forms known as RpiA and RpiB, both of which catalyze the same reaction, and most organisms express one or both of these enzymes. | ||
The functional and structural properties of RpiA have been determined from organisms including ''Escherichia coli, Pyrococcus horikoshii, Saccharomyces cerevisiae,'' among others<ref name="rpi">PMID:12517338</ref>. These studies have revealed an important role RpiA plays in the Calvin cycle in plants and pentose phosphate pathway in both plants and animals <ref name="rpi2">PMID:19214439</ref>. The sequence conservation among RpiA subfamilies also shows the considerable evolutionary significance in preserving its function across different organisms. | The functional and structural properties of '''RpiA''' have been determined from organisms including ''Escherichia coli, Pyrococcus horikoshii, Saccharomyces cerevisiae,'' among others<ref name="rpi">PMID:12517338</ref>. These studies have revealed an important role RpiA plays in the [[Calvin cycle]] in plants and pentose phosphate pathway in both plants and animals <ref name="rpi2">PMID:19214439</ref>. The sequence conservation among RpiA subfamilies also shows the considerable evolutionary significance in preserving its function across different organisms. | ||
*'''RpiB''' does not exist in humans and is structurally unrelated to RplA<ref>PMID:27230471</ref>. | |||
==Function== | ==Function== | ||
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==Structure== | ==Structure== | ||
The structure of RpiA has been identified in many organisms including ''E. coli'' and ''Vibrio vulnificus''. The crystallized RpiA structure from both of these organisms is highly conserved in many respects. RpiA exists as a dimer with pseudo-2-fold symmetry, the interface of the dimer is composed of six different segments, which contain a number of interactions occurring between <scene name='Sandbox_Reserved_305/Alpha_helices/2'> α-helices </scene> and <scene name='Sandbox_Reserved_305/Beta_sheets/1'> β-sheets </scene>. Two salt bridges also link <scene name=' | The structure of RpiA has been identified in many organisms including ''E. coli'' and ''Vibrio vulnificus''. The crystallized RpiA structure from both of these organisms is highly conserved in many respects. RpiA exists as a dimer with pseudo-2-fold symmetry, the interface of the dimer is composed of six different segments, which contain a number of interactions occurring between <scene name='Sandbox_Reserved_305/Alpha_helices/2'> α-helices </scene> and <scene name='Sandbox_Reserved_305/Beta_sheets/1'> β-sheets </scene>. Two salt bridges also link <scene name='44/446270/Cv/1'>Lys104 and Glu183</scene> of the same subunit. The <scene name='Sandbox_Reserved_305/Activesite/3'>RpiA and R5P complex</scene> occurs through the interaction between the ligand (R5P) and the following residues in the RpiA: <scene name='44/446270/Cv/3'>Gly97, Asp84, Lys121, Lys7, Thr31, and Ser30</scene>. RpiA contains <scene name='44/446270/Cv/4'>two sites for this interaction allowing two R5Ps to interact with one RpiA</scene>. The VvRpiA-R5P complex resembles the ''E. coli'' RpiA-A5P complex; however the VvRpiA-A5P complex reveals a different position than the R5P binding mode. The A5P interacts with the following residues: Asp8, Lys7, Ser30, Asp118 and Lys121. | ||
==Medical and Future Implications== | ==Medical and Future Implications== | ||
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==3D structures of ribose-5-phosphate isomerase== | ==3D structures of ribose-5-phosphate isomerase== | ||
[[Ribose-5-phosphate isomerase 3D structures]] | |||
</StructureSection> | |||
==References== | ==References== | ||
<references/> | <references/> | ||
*Created with the participation of [[User:Jasmeet Bhullar|Jasmeet Bhullar]]. | |||
[[Category:Topic Page]] | [[Category:Topic Page]] | ||