Three-dimensional structures aconitase

Thiosulfate cyanide sulfurtransferase symmetry in 78 TTiiouridine 234 Three-dimensional structures of aconitase 689 adenylate kinase 655 aldehyde oxido-reductase 891 D-amino acid oxidase 791 a-amylase, pancreatic 607 aspartate aminotransferase 57,135 catalytic intermediates 752 aspartate carbamyltransferase 348 aspartate chemoreceptor 562 bacteriophage P22 66 cadherin 408 calmodulin 317 carbonic acid anhydrase I 679 carboxypeptidase A 64 catalase 853 cholera toxin 333, 546 chymotrypsin 611 citrate synthase 702, 703 cutinase 134 cyclosporin 488 cytochrome c 847 cytochrome c peroxidase 849 dihydrofolate reductase 807 DNA 214, 223,228,229, 241 DNA complex... 

Ogston offered an explanation, called the three-point attachment proposal, that was to initiate the concept of prochirality. If citrate is represented as a three-dimensional structure (Fig. 12-12), then on the assumption that a three-point attachment to aconitase is necessary for catalysis, it is apparent that citrate can only be accommodated in one orientation. The removal of the elements of water can then only occur from one particular half of the symmetrical molecule. 

But we have a dilemma. When comparing three-dimensional structures, what should be compared to what In the case of direct comparisons of citrate ions, there W s a central tetrahedral carbon atom in the molecule and all citrate ions could be laid on top of each other, as shown in Figure 16.1, with the central three carbon atoms superimposed. When, however, citrate and isocitrate are compared, it is less clear how the comparison should be made. In the example of aconitase substrates, it was made by reasoning that the enzyme probably holds on to the... 

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