Publication Abstract from PubMed
Previously determined crystal structures of the zinc enzyme Escherichia coli class II fructose-1,6-bisphosphate aldolase display good agreement for the protein structure but a differing metal-ion organization in the active site. The structure of the enzyme with Cd(2+) in place of Zn(2+) has now been determined to 2.0 A resolution to facilitate cation identification. The protein structure was essentially identical to other structures and five Cd(2+) positions were identified. Two of the cations are at the active site; one corresponds to the catalytic ion and the other provides a structural contribution. These Cd(2+) sites are equivalent to two Zn(2+) ions observed when the enzyme is complexed with a transition-state mimic and confirm our assignment of the roles played by these ions.
The organization of divalent cations in the active site of cadmium Escherichia coli fructose-1,6-bisphosphate aldolase.,Hall DR, Kemp LE, Leonard GA, Marshall K, Berry A, Hunter WN Acta Crystallogr D Biol Crystallogr. 2003 Mar;59(Pt 3):611-4. Epub 2003, Feb 21. PMID:12595741[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.