Novel active site in Escherichia coli fructose 1,6-bisphosphate aldolase.
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Blom NS, Tetreault S, Coulombe R, Sygusch J
Novel active site in Escherichia coli fructose 1,6-bisphosphate aldolase.
Nat Struct Biol. 1996 Oct;3(10):856-62.
- PubMed ID
- 8836102 [ View in PubMed]
- Abstract
The molecular architecture of the Class II E. coli fructose 1,6-bisphosphate aldolase dimer was determined to 1.6 A resolution. The subunit fold corresponds to a singly wound alpha/beta-barrel with an active site located on the beta-barrel carboxyl side of each subunit. In each subunit there are two mutually exclusive zinc metal ion binding sites, 3.2 A apart; the exclusivity is mediated by a conformational transition involving side-chain rotations by chelating histidine residues. A binding site for K+ and NH4+ activators was found near the beta-barrel centre. Although Class I and Class II aldolases catalyse identical reactions, their active sites do not share common amino acid residues, are structurally dissimilar, and from sequence comparisons appear to be evolutionary distinct.