Sandbox Reserved 342
From Proteopedia
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| - | Xanthine-guanine Phosphoribosyltansferase (XGPRT) is one of three purine phosphoribosyltransferases (PRTases) that are part of the purine salvage pathway in Escherichia coli <ref name="Vos"> PMID:9743633 </ref>; the other two PRTases in the pathway are HPRT and APRT<ref name="Vos"/> | + | Xanthine-guanine Phosphoribosyltansferase (XGPRT) is one of three purine phosphoribosyltransferases (PRTases) that are part of the purine salvage pathway in Escherichia coli. |
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| + | <ref name="Vos"> PMID:9743633 </ref>; the other two PRTases in the pathway are HPRT and APRT<ref name="Vos"/> | ||
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=MECHANISM= | =MECHANISM= | ||
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==Recognition== | ==Recognition== | ||
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==Catalysis== | ==Catalysis== | ||
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Magnesium and other divalent cations are necessary for catalysis<ref name="Vos"/>. | Magnesium and other divalent cations are necessary for catalysis<ref name="Vos"/>. | ||
| - | =Importance= | ||
| - | =Additional Resources= | ||
=References= | =References= | ||
<references/> | <references/> | ||
Revision as of 02:18, 3 April 2011
| This Sandbox is Reserved from January 10, 2010, through April 10, 2011 for use in BCMB 307-Proteins course taught by Andrea Gorrell at the University of Northern British Columbia, Prince George, BC, Canada. |
To get started:
More help: Help:Editing |
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| 1a96, resolution 2.00Å () | |||||||||
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| Ligands: | , , , | ||||||||
| Gene: | GPT (Escherichia coli) | ||||||||
| Activity: | Xanthine phosphoribosyltransferase, with EC number 2.4.2.22 | ||||||||
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| Resources: | FirstGlance, OCA, RCSB, PDBsum | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
XANTHINE-GUANINE PHOSPHORIBOSYLTRANSFERASE
Contents |
Introduction
Xanthine-guanine Phosphoribosyltansferase (XGPRT) is one of three purine phosphoribosyltransferases (PRTases) that are part of the purine salvage pathway in Escherichia coli.
[1]; the other two PRTases in the pathway are HPRT and APRT[1]
Structure
PRTase structures fall into two groups, type I and Type II[1]. XGTPase has a conserved sequence,85-IVIDDLVDTG-94, which is called the PRib-PP (5-phospho-a-D-ribosyl-1-pyrophosphate) binding site[1]. This binding site features two adjacent acidic residues, which are surrounded by hydrophobic residues[1]. There is a five-stranded b-sheet surrounded by three or four a-helices that creates a conserved structural core containing the PRib-PP binding site[1]. Another region of the sequence in XGTPase forms a lobe, which is involved in substrate recognition[1].
Function
XGRT is an enzyme that catalyzes the conversion of guanine, xanthine, and sometimes hypoxanthine, to GMP, XMP, and IMP [1].
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