Metallo-aldolase

This is the mechanism of catalysis by aldolases which occur in plant and animal tissues (lysine aldolases or class I aldolases). A second group of these enzymes often produced by microorganisms contains a metal ion (metallo-aldolases). This group is involved in accelerating retroaldol condensations through electrophihc reactions with carbonyl groups ... 

The L-rhamnulose 1-phosphate aldolase (RhuA EC 4.1.2.19) is found in the microbial degradation of L-rhamnose which, after conversion into the corresponding ketose 1-phosphate 44, is cleaved into 41 and L-lactaldehyde (l-16). The RhuA has been isolated from E. coli [336-339], and characterized as a metallo-protein [194,340,341]. Cloning was reported for the E. coli [342,343] and Salmonella typhimurium [344] genes, and construction of an efficient overexpression system [195,220] has set the stage for crystallization of the homotetrameric E. coli protein for the purposes of an X-ray structure analysis [345]. 

On the basis of a catalytic system previously developed by the same group, Nicholls and collaborators [51] reported the preparation of an imprinted polymer for enantioselective formation of a C-C bond with properties of a metallo-enzyme aldolase type II. Polymers were imprinted using the two enantiomers of a 1,3-diketone, the (l.S, 35,45)-(75), and the corresponding (l/ ,3/ ,4/ )-(75), together with two 4-vinyl-pyridine held in place by a Co(II). The cross-aldol condensation... 

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