Fructose Bisphosphate Aldolase

Fructose biphosphate aldolase is an enzyme in glycolysis. It catalyzes the breakdown of fructose-1,6-biophosphate into dihydroxyacetone phosphate (DHAP) and glyceraldehyde-2-phosphate (GAP). The reaction is an aldol cleavage, or otherwise termed, retro aldo condensation. Catalysis occurs by the formation of a Schiff base (an imine resulting from a ketone and amine) from the amine of the aldolase's Lys229 and the open-ring form of FBP accompanied by stabilization from Asp33. <scene name='Austin_Drake_Sandbox/Catalytic_site/3'>Catalytic Site</scene> <scene name='Austin_Drake_Sandbox/Catalytic_site_w_water/2'>Catalytic Site Closeup</scene> <ref name="jmol">Jmol: an open-source Java viewer for chemical structures in 3D. http://www.jmol.org/</ref> Aldol cleavage produces GAP and an enamine precursor to DHAP. Tautomerization, protonation and the hydrolysis of the Schiff base produce the final product of DHAP and the active enzyme.<ref>Voet, D, Voet, J, & Pratt, C. (2008). Fundamentals of biochemistry, third edition. Hoboken, NJ: Wiley & Sons, Inc.</ref> The enzyme is an a/B protein. It is part of the aldolase superfamily and the class I aldoses<ref>Protein: fructose-1,6-bisphosphate aldolase from human (homo sapiens), muscle isozyme. (2009). Retrieved from http://scop.mrc-lmb.cam.ac.uk</ref><scene name='Austin_Drake_Sandbox/Different_colors/1'>a Helices and B sheets</scene> can be seen in their specific regions concentrically located around the active site.