==Mechanism of displacement of a catalytically essential loop from the active site of fructose-1,6-bisphosphatase==

<StructureSection load='2f3b' size='340' side='right' caption='[[2f3b]], [[Resolution|resolution]] 1.80&Aring;' scene=''>

<table><tr><td colspan='2'>[[2f3b]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Pig Pig]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2F3B OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2F3B FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=F6P:FRUCTOSE-6-PHOSPHATE'>F6P</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></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=2f3b FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2f3b OCA], [http://pdbe.org/2f3b PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2f3b RCSB], [http://www.ebi.ac.uk/pdbsum/2f3b PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2f3b ProSAT]</span></td></tr>

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

AMP triggers a 15 degrees subunit-pair rotation in fructose-1,6-bisphosphatase (FBPase) from its active R-state to its inactive T-state. During this transition, a catalytically essential loop (residues 50-72) leaves its active (engaged) conformation. Structures of Ile10--&gt;Asp FBPase and molecular dynamic simulations here reveal factors responsible for loop displacement. AMP/Mg2+ and AMP/Zn2+ complexes of Asp10 FBPase are in intermediate quaternary conformations (completing 12 degrees of subunit-pair rotation), but the complex with Zn2+ provides the first instance of an engaged loop in a near-T quaternary state. The 12 degrees subunit-pair rotation generates close contacts involving the hinges (residues 50-57) and hairpin turns (residues 58-72) of the engaged loops. Additional subunit-pair rotation toward the T-state would make such contacts unfavorable, presumably causing displacement of the loop. Targeted molecular dynamics simulations reveal no steric barriers to subunit-pair rotations up to 14 degrees , followed by the displacement of the loop from the active site. Principal component analysis reveals high-amplitude motions that exacerbate steric clashes of engaged loops in the near-T state. The results of simulations and crystal structures are in agreement: subunit-pair rotations just short of the canonical T-state, coupled with high-amplitude modes, sterically displace the dynamic loop from the active site.

Mechanism of Displacement of a Catalytically Essential Loop from the Active Site of Mammalian Fructose-1,6-bisphosphatase.,Gao Y, Iancu CV, Mukund S, Choe JY, Honzatko RB Biochemistry. 2013 Jul 11. PMID:23844654<ref>PMID:23844654</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

</div>

<div class="pdbe-citations 2f3b" style="background-color:#fffaf0;"></div>

==See Also==

*[[Fructose-1%2C6-bisphosphatase|Fructose-1%2C6-bisphosphatase]]

== References ==

<references/>

[[Category: Fructose-bisphosphatase]]

[[Category: Pig]]

[[Category: 6-bisphosphatase]]

[[Category: Loop diengagement]]