2-keto-3-deoxy-manno-octosonate

Pyruvate-dependent lyases serve catabolic functions in vivo in the degradation of sialic acids and KDO (2-keto-3-deoxy-manno-octosonate), and in that of 2-keto-3-deoxy aldonic acid intermediates from hexose or pentose catabolism. 

Natural substrates of the 2-keto-3-deoxy-manno-octoson c acid aldolase, and nonnatural sialic acids obtained by KdoA catalysis. 

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 KdoA enzyme is involved in the catabolism of the eight-carbon sugar, 2-Keto-3-deoxy-manno-octosonate, by reversibly degrading it to o-arabinose and pyruvate [139], KdoA has broad substrate spedfidty for aldehydes while pyruvate was found to be irreplaceable (Table 10.15) [139,140], The stereochemical course of the aldol addition is invariable always involving re-face attack on the aldehyde carbonyl. On the basis of the results published so far, it may be concluded that a (3R)-configuration of the acceptor is necessary (but not suf-fident), and that stereochemical requirements at are less stringent [140]. 

Aldol Addition of Pyruvate to o-Arabinose and Anaiogs Cataiyzed by 2-Keto-3-deoxy-manno-octosonate (KDO) aidoiase (KdoA). 

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