2-Keto-3-deoxy-gluconate aldolase

Gluconolactonase [Lactonase] (3.1.1.17) is present. Phospogluconate dehydratase (4.2.1.12) is present. Phospho-2-keto-3-deoxy-gluconate aldolase (4.1.2.14) is present. 

Phospho-2-keto-3-deoxygluconate aldolase, an enzyme in the Entner-Doudoroff pathway, that catalyzes the cleavage 6-phospho-2-keto-3-deoxy-D-gluconate to form pyruvate and D-glyceraldehyde 3-phosphate. 

Keto-3-deoxy-6-phospho-D-gluconate Aldolase= 2-Keto-4-bydroxyglutarate Aldolase... 

The analogous reduction experiment carried out with pyruvate plus 2-keto-3-deoxy-6-phospho-D-gluconate aldolase results in almost equal reduction at both diastereotopic faces of the ketimine (178). Apparently, solvent accessibility to the ketimine is not uniformly restricted among all aldolases. 

Stereocomplementary sets of pyravate dependent aldolases. /V-acetyIneuraminic acid aldolase (NeuA EC 4.1.3.3), 2-keto-3-deoxy-manno-octosonate (KDO) aldolase (KdoA EC 4.1.2.23), 2-keto-3-deoxy-6-phospho-D-gluconate aldolases (GIcA EC 4.1.2.14)) and 2-keto-3-deoxy-6-phospho-D-galactonate aldolases (GalA EC4.1.2.21). 

The 2-keto-3-deoxy-aldonic acid (phosphate) aldolases from Pseudomonas strains - 3-deoxy-2-keto-L-arabonate (F.C 4.1.2.18), 3-deoxy-2-keto-D-xylonate (EC 4.1.2.28), 3-deoxy-2-keto-6-phospho-D-gluconate (EC 4.1.2.14) and 3-deoxy-2-keto-6-phospho-D-galactonate aldolase (EC 4.1.2.21) - appear to be specific even for the acceptor components, but allow stereoselective syntheses of the respective natural substrates29. 

Figure 10.11 Aldol reactions catalyzed in vivo by the 2-keto-3-deoxy-6-phospho-o-gluconate and 2-keto-3-deoxy-6-phospho-o-galactonate aldolases.

The first such case was concerned with the limited substrate acceptance of d-2-keto-3-deoxy-6-phospho-gluconate (KDPG) aldolase (161). This catalyzes the (reversible) reaction of pyruvate (41) to certain chiral aldehydes such as 42, with formation of aldol products such as 43. It was known that this aldolase is highly specific for chir l-phosphorylated aldehydes with the d configuration at the C2 position leading stereoselectively to a precursor of the corresponding d sugar such as 44 (162) ... 

The 2-keto-3-deoxy-6-phospho-D-gluconate (11) aldolase (KDPGlc aldolase or KdgA EC 4.1.2.14) provides the basis of the Entner-Doudoroff pathway that is used by many species of bacteria for the degradation of 6-phosphogluconate... 

D have an a-helix preceding the alft barrel this helix blocks the N-terminal end of the barrel fructose-biphosphate aldolase, 2-keto-3-deoxy-6-phospho- gluconate... 

Other pyruvate- and phosphoenolpyruvate-dependent aldolases have been isolated and purified, but have not yet been extensively investigated for synthetic use. Those showing promise for future applications include, 3-deoxy-D-arabino-2-heptulosonic acid 7-phosphate (DAHP) synthetase (EC 4.1.2.15), 2-keto-4-hydroxyglutarate (KHG) aldolase (EC 4.1.2.31), and 2-keto-3-deoxy-D-gluconate (KDG) aldolase (EC 4.1.2.20). DAHP synthetase has been used... 

Addition of Pyruvate to Aldehydes Catalyzed by 2-Keto-3-deoxy-6-phospho-D-gluconate (GIcA), 2-Keto 3- deoxy-6-phospho-D-galactonate aldolases (GalA), and Macrophomate Synthase (MPS)... 

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