Fructose bisphosphate aldolases

Reaction 4 Cleavage of Fructose-1,6-bisP by Fructose Bisphosphate Aldolase... 

Fructose bisphosphate aldolase of animal muscle is a Class I aldolase, which forms a Schiff base or imme intermediate between the substrate (fructose-1,6-bisP or dihydroxyacetone-P) and a lysine amino group at the enzyme active site. The chemical evidence for this intermediate comes from studies with the aldolase and the reducing agent sodium borohydride, NaBH4. Incubation of fructose bisphosphate aldolase with dihydroxyacetone-P and NaBH4 inactivates the enzyme. Interestingly, no inactivation is observed if NaBH4 is added to the enzyme in the absence of substrate. 

Subsequent action by fructose-l-phosphate aldolase cleaves fructose-l-P in a manner like the fructose bisphosphate aldolase reaction to produce dihy-droxyacetone phosphate and D-glyceraldehyde ... 

A good example of such a cleavage is the fructose bisphosphate aldolase reaction (see Chapter 19, Figure 19.14a). 

Fructose bisphosphate aldolase— aldolase Hydroxymethylglutaryl-CoA lyase Hydroxymethylglutaryl-CoA synthase Citrate synthase ATP-citrate lyase... 

Fructose-bisphosphate aldolase, which also acts on fructose-1-phosphate, is the enzyme deficient in hereditary fructose intolerance (HFI, MIM 229 600). 

Misset, 0. Opperdoes, F.R. Simultaneous purification of hexokinase, class-I fructose-bisphosphate aldolase, triosephosphate isomerase and phosphoglycerate kinase from Trypanosoma brucei. Eur. J. Biochem., 144, 475-483 (1984)... 

Type I aldolases, which include the most studied mammalian enzymes, have a more complex mechanism involving intermediate Schiff base forms (Eq. 13-36, steps a, V, c, d ).m The best known members of this group are the fructose bisphosphate aldolases (often referred to simply as aldolases), which cleave fructose-1,6-P2 during glycolysis (Fig. 10-2, step e). 

Fructose bisphosphate aldolases 699 Fructose 6-phosphate 535, 693s Fructose 6-phosphate kinase 656 Fructose-1,6-bisphosphatase 645 Fructose-2,6-bisphosphatase 646 Fruit fly. See Drosophilia melanogaster Fucose (Fuc) 165s L-Fucose isomerase 693 Fucosyltransferase 184 Fucoxanthin 22... 

In proteins with a symmetric structure, circular permutation can account for the shift of active-site residues over the course of evolution. A very good model of symmetric proteins are the (/Ja)8-barrel enzymes with their typical eightfold symmetry. Circular permutation is characterized by fusion of the N and C termini in a protein ancestor followed by cleavage of the backbone at an equivalent locus around the circular structure. Both fructose-bisphosphate aldolase class I and transaldolase belong to the aldolase superfamily of (a/J)8-symmetric barrel proteins both feature a catalytic lysine residue required to form the Schiff base intermediate with the substrate in the first step of the reaction (Chapter 9, Section 9.6.2). In most family members, the catalytic lysine residue is located on strand 6 of the barrel, but in transaldolase it is not only located on strand 4 but optimal sequence and structure alignment with aldolase class I necessitates rotation of the structure and thus circular permutation of the jS-barrel strands (Jia, 1996). 

D fructose bisphosphate aldolase none aldol cleavage... 

E. coli Fructose Bisphosphate Aldolase IDOS His 37 His 51 Glu 63 HiSa/i (N)... 

CG32626 Purine base metabolism Thymidylate synthase Fructose bisphosphate aldolase Creatine kinase Malate dehydrogenase Carbonic anhydrase III Catalase... 

Littlechild JA, Watson HC (1993) A data-based reaction mechanism for type-i fructose bisphosphate aldolase. Trends Biochem Sci 18 36... 

Callens, M., Kuntz, D. A. and Opperdoes, F. R. (1991) Kinetic properties of fructose bisphosphate aldolase from Trypanosoma brucei compared to aldolases from rabbit muscle and Staphylococcus aureus. Mol. Biochem. Parasitol. 47 1 10. 

Clayton, C. (1986) Structure and regulated expression of genes encoding fructose bisphosphate aldolase in Trypanosoma brucei. EMBO J. 4 2997-3003. 

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