1nv3: Difference between revisions
New page: left|200px<br /><applet load="1nv3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1nv3, resolution 2.0Å" /> '''Fructose-1,6-Bisphosp... |
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[[Image:1nv3.gif|left|200px]]<br /><applet load="1nv3" size=" | [[Image:1nv3.gif|left|200px]]<br /><applet load="1nv3" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1nv3, resolution 2.0Å" /> | caption="1nv3, resolution 2.0Å" /> | ||
'''Fructose-1,6-Bisphosphatase Complex with Magnesium, Fructose-6-Phosphate, Phosphate and Thallium (100 mM)'''<br /> | '''Fructose-1,6-Bisphosphatase Complex with Magnesium, Fructose-6-Phosphate, Phosphate and Thallium (100 mM)'''<br /> | ||
==Overview== | ==Overview== | ||
Fructose-1,6-bisphosphatase requires divalent cations (Mg2+, Mn2+, or | Fructose-1,6-bisphosphatase requires divalent cations (Mg2+, Mn2+, or Zn2+) for catalysis, but a diverse set of monovalent cations (K+, Tl+, Rb+, or NH(4)(+)) will further enhance enzyme activity. Here, the interaction of Tl+ with fructose-1,6-bisphosphatase is explored under conditions that support catalysis. On the basis of initial velocity kinetics, Tl+ enhances catalysis by 20% with a K(a) of 1.3 mm and a Hill coefficient near unity. Crystal structures of enzyme complexes with Mg2+, Tl+, and reaction products, in which the concentration of Tl+ is 1 mm or less, reveal Mg2+ at metal sites 1, 2, and 3 of the active site, but little or no bound Tl+. Intermediate concentrations of Tl+ (5-20 mm) displace Mg2+ from site 3 and the 1-OH group of fructose 6-phosphate from in-line geometry with respect to bound orthophosphate. Loop 52-72 appears in a new conformational state, differing from its engaged conformation by disorder in residues 61-69. Tl+ does not bind to metal sites 1 or 2 in the presence of Mg2+, but does bind to four other sites with partial occupancy. Two of four Tl+ sites probably represent alternative binding sites for the site 3 catalytic Mg2+, whereas the other sites could play roles in monovalent cation activation. | ||
==About this Structure== | ==About this Structure== | ||
1NV3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with F6P, MG, PO4 and TL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Fructose-bisphosphatase Fructose-bisphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.11 3.1.3.11] Full crystallographic information is available from [http:// | 1NV3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with <scene name='pdbligand=F6P:'>F6P</scene>, <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=TL:'>TL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Fructose-bisphosphatase Fructose-bisphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.11 3.1.3.11] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NV3 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Sus scrofa]] | [[Category: Sus scrofa]] | ||
[[Category: Choe, J.]] | [[Category: Choe, J.]] | ||
[[Category: Fromm, H | [[Category: Fromm, H J.]] | ||
[[Category: Honzatko, R | [[Category: Honzatko, R B.]] | ||
[[Category: Iancu, C | [[Category: Iancu, C V.]] | ||
[[Category: F6P]] | [[Category: F6P]] | ||
[[Category: MG]] | [[Category: MG]] | ||
| Line 27: | Line 27: | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:10:27 2008'' | ||
Revision as of 15:10, 21 February 2008
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Fructose-1,6-Bisphosphatase Complex with Magnesium, Fructose-6-Phosphate, Phosphate and Thallium (100 mM)
OverviewOverview
Fructose-1,6-bisphosphatase requires divalent cations (Mg2+, Mn2+, or Zn2+) for catalysis, but a diverse set of monovalent cations (K+, Tl+, Rb+, or NH(4)(+)) will further enhance enzyme activity. Here, the interaction of Tl+ with fructose-1,6-bisphosphatase is explored under conditions that support catalysis. On the basis of initial velocity kinetics, Tl+ enhances catalysis by 20% with a K(a) of 1.3 mm and a Hill coefficient near unity. Crystal structures of enzyme complexes with Mg2+, Tl+, and reaction products, in which the concentration of Tl+ is 1 mm or less, reveal Mg2+ at metal sites 1, 2, and 3 of the active site, but little or no bound Tl+. Intermediate concentrations of Tl+ (5-20 mm) displace Mg2+ from site 3 and the 1-OH group of fructose 6-phosphate from in-line geometry with respect to bound orthophosphate. Loop 52-72 appears in a new conformational state, differing from its engaged conformation by disorder in residues 61-69. Tl+ does not bind to metal sites 1 or 2 in the presence of Mg2+, but does bind to four other sites with partial occupancy. Two of four Tl+ sites probably represent alternative binding sites for the site 3 catalytic Mg2+, whereas the other sites could play roles in monovalent cation activation.
About this StructureAbout this Structure
1NV3 is a Single protein structure of sequence from Sus scrofa with , , and as ligands. Active as Fructose-bisphosphatase, with EC number 3.1.3.11 Full crystallographic information is available from OCA.
ReferenceReference
Interaction of Tl+ with product complexes of fructose-1,6-bisphosphatase., Choe JY, Nelson SW, Fromm HJ, Honzatko RB, J Biol Chem. 2003 May 2;278(18):16008-14. Epub 2003 Feb 20. PMID:12595529
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