Sandbox Reserved 769: Difference between revisions
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==Tryptophan Synthase== | ==Tryptophan Synthase== | ||
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Tryptophan synthase is an enzyme that catalyzes the final two steps in the biosynthesis of tryptophan. It is commonly found in Eubacteria, Archaebacteria, Protista, Fungi, and Plantae. However, it is absent from Animalia. <ref name="info">http://en.wikipedia.org/wiki/Tryptophan_synthase</ref> | Tryptophan synthase is an enzyme that catalyzes the final two steps in the biosynthesis of tryptophan. It is commonly found in Eubacteria, Archaebacteria, Protista, Fungi, and Plantae. However, it is absent from Animalia. <ref name="info">http://en.wikipedia.org/wiki/Tryptophan_synthase</ref> | ||
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==General Information== | ==General Information== | ||
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'''Gene Name''': trpA, trpB<ref name="cite2">http://www.uniprot.org/uniprot/P00929</ref> | '''Gene Name''': trpA, trpB<ref name="cite2">http://www.uniprot.org/uniprot/P00929</ref> | ||
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==Enzyme Structure== | ==Enzyme Structure== | ||
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'''Hydrophobic channel:''' The α and β active sites are separated by a | |||
'''Hydrophobic channel:''' The α and β active sites are separated by a 30 Å long hydrophobic channel contained within the enzyme allowing for the diffusion of indole. If the channel did not exist, the indole formed at an α active site would quickly diffuse away and be lost to the cell as it is hydrophobic and can easily cross membranes. As such, the channel is essential for enzyme complex function<ref name="cite6">http://www.annualreviews.org/doi/abs/10.1146/annurev.biochem.70.1.149</ref> | |||
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==Enzyme Mechanism== | ==Enzyme Mechanism== | ||
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Indole-3-glycerol-phosphate (IGP) is cleaved by the tryptophan synthase α-subunit (TSA) to indole and glyceraldehyde-3-phosphate (GDP) This is known as the α-reaction. The alpha reaction is reversible. Then indole is transported via a 30 Å intermolecular tunnel to the tryptophan synthase β-subunits (TSB) that catalyze the condensation of indole and serine to tryptophan. This is known as the β-reaction and it is a pyridoxal-5-phosphate (PLP) dependent reaction. | |||
[[Image:TrpSyn.gif]] | [[Image:TrpSyn.gif]] | ||
==References== | ==References== | ||
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<references /> | <references /> | ||
