The organization of divalent cations in the active site of cadmium Escherichia coli fructose-1,6-bisphosphate aldolase.
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.
Hall
David R
DR
Division of Biological Chemistry and Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland.
Kemp
Lauris E
LE
Leonard
Gordon A
GA
Marshall
Karen
K
Berry
Alan
A
Hunter
William N
WN
D001665:Binding Sites; D002104:Cadmium / Q000737:chemistry*; D002384:Catalysis; D002412:Cations / Q000737:chemistry; D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D005634:Fructose-Bisphosphate Aldolase / Q000737:chemistry* / Q000302:isolation & purification; D008958:Models, Molecular; D015032:Zinc / Q000737:chemistry
D002412:Cations; D002104:Cadmium; D005634:Fructose-Bisphosphate Aldolase; D015032:Zinc