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2fw6

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Revision as of 08:51, 24 December 2014

Structure of PurE (N5-carboxyaminoimidazole ribonucleotide mutase) mutant H59N from the acidophilic bacterium Acetobacter aceti, at pH 5.4

Structural highlights

2fw6 is a 2 chain structure with sequence from Acetobacter aceti. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Related:	1u11
Gene:	purE (Acetobacter aceti)
Resources:	FirstGlance, OCA, RCSB, PDBsum

Function

[Q2QJL3_ACEAC] Catalyzes the conversion of N5-carboxyaminoimidazole ribonucleotide (N5-CAIR) to 4-carboxy-5-aminoimidazole ribonucleotide (CAIR) (By similarity).[PIRNR:PIRNR001338]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

N5-carboxyaminoimidazole ribonucleotide (N5-CAIR) mutase (PurE) catalyzes the reversible interconversion of acid-labile compounds N5-CAIR and 4-carboxy-5-aminoimidazole ribonucleotide (CAIR). We have examined PurE from the acidophilic bacterium Acetobacter aceti (AaPurE), focusing on its adaptation to acid pH and the roles of conserved residues His59 and His89. Both AaPurE and Escherichia coli PurE showed quasi-reversible acid-mediated inactivation, but wt AaPurE was much more stable at pH 3.5, with a > or = 20 degrees C higher thermal unfolding temperature at all pHs. His89 is not essential and does not function as part of a proton relay system. The kcat pH-rate profile was consistent with the assignment of pK1 to unproductive protonation of bound nucleotide and pK2 to deprotonation of His59. A 1.85 A resolution crystal structure of the inactive mutant H59N-AaPurE soaked in CAIR showed that protonation of CAIR C4 can occur in the absence of His59. The resulting species, modeled as isoCAIR [4(R)-carboxy-5-iminoimidazoline ribonucleotide], is strongly stabilized by extensive interactions with the enzyme and a water molecule. The carboxylate moiety is positioned in a small pocket proposed to facilitate nucleotide decarboxylation in the forward direction (N5-CAIR --> CAIR) [Meyer, E., Kappock, T. J., Osuji, C., and Stubbe, J. (1999) Biochemistry 38, 3012-3018]. Comparisons with model studies suggest that in the reverse (nonbiosynthetic) direction PurE favors protonation of CAIR C4. We suggest that the essential role of protonated His59 is to lower the barrier to decarboxylation by stabilizing a CO2-azaenolate intermediate.

Biochemical and structural studies of N5-carboxyaminoimidazole ribonucleotide mutase from the acidophilic bacterium Acetobacter aceti.,Constantine CZ, Starks CM, Mill CP, Ransome AE, Karpowicz SJ, Francois JA, Goodman RA, Kappock TJ Biochemistry. 2006 Jul 11;45(27):8193-208. PMID:16819818^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Constantine CZ, Starks CM, Mill CP, Ransome AE, Karpowicz SJ, Francois JA, Goodman RA, Kappock TJ. Biochemical and structural studies of N5-carboxyaminoimidazole ribonucleotide mutase from the acidophilic bacterium Acetobacter aceti. Biochemistry. 2006 Jul 11;45(27):8193-208. PMID:16819818 doi:http://dx.doi.org/10.1021/bi060465n

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2fw6"

@@ Line 3: / Line 3: @@
 == Structural highlights ==
 <table><tr><td colspan='2'>[[2fw6]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Acetobacter_aceti Acetobacter aceti]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FW6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2FW6 FirstGlance]. <br>
-</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene><br>
+</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene></td></tr>
-<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1u11|1u11]]</td></tr>
+<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1u11|1u11]]</td></tr>
-<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">purE ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=435 Acetobacter aceti])</td></tr>
+<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">purE ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=435 Acetobacter aceti])</td></tr>
-<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2fw6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2fw6 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2fw6 RCSB], [http://www.ebi.ac.uk/pdbsum/2fw6 PDBsum]</span></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2fw6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2fw6 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2fw6 RCSB], [http://www.ebi.ac.uk/pdbsum/2fw6 PDBsum]</span></td></tr>
-<table>
+</table>
+== Function ==
+[[http://www.uniprot.org/uniprot/Q2QJL3_ACEAC Q2QJL3_ACEAC]] Catalyzes the conversion of N5-carboxyaminoimidazole ribonucleotide (N5-CAIR) to 4-carboxy-5-aminoimidazole ribonucleotide (CAIR) (By similarity).[PIRNR:PIRNR001338]
 == Evolutionary Conservation ==
 [[Image:Consurf_key_small.gif|200px|right]]
@@ Line 34: / Line 36: @@
 </StructureSection>
 [[Category: Acetobacter aceti]]
-[[Category: Kappock, T J.]]
+[[Category: Kappock, T J]]
-[[Category: Starks, C M.]]
+[[Category: Starks, C M]]
 [[Category: Acidophile]]
 [[Category: Lyase]]
 [[Category: Pure]]
 [[Category: Purine biosynthesis]]

2fw6

From Proteopedia

Revision as of 08:51, 24 December 2014

Structure of PurE (N5-carboxyaminoimidazole ribonucleotide mutase) mutant H59N from the acidophilic bacterium Acetobacter aceti, at pH 5.4

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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