1QML

Hg complex of yeast 5-aminolaevulinic acid dehydratase

Summary for 1QML

• Entry DOI: 10.2210/pdb1qml/pdb
• Related: 1AW5 1QMK 1QNV 1YLV
• Descriptor: 5-AMINOLAEVULINIC ACID DEHYDRATASE, MERCURY (II) ION (3 entities in total)
• Functional Keywords: dehydratase, aldolase, tim barrel, tetrapyrrole synthesis
• Biological source: SACCHAROMYCES CEREVISIAE (BAKER'S YEAST)
• Total number of polymer chains: 1
• Total formula weight: 37985.75

Authors

Erskine, P.T.,Senior, N.,Warren, M.J.,Wood, S.P.,Cooper, J.B. (deposition date: 1999-10-02, release date: 2000-10-06, Last modification date: 2023-12-13)

Primary citation

Erskine, P.T.,Duke, E.M.H.,Tickle, I.J.,Senior, N.M.,Warren, M.J.,Cooper, J.B.
MAD Analyses of Yeast 5-Aminolaevulinic Acid Dehydratase. Their Use in Structure Determination and in Defining the Metal Binding Sites
Acta Crystallogr.,Sect.D, 56:421-, 2000

PubMed Abstract: MAD experiments attempting to solve the structure of 5--aminolaevulinic acid dehydratase using Zn and Pb edges are described. The data obtained proved insufficient for a complete structure solution but were invaluable in subsequent identification of metal-binding sites using anomalous difference Fourier analyses once the structure of the enzyme had been solved. These sites include the highly inhibitory substitution of an enzymic cofactor Zn(2+) ion by Pb(2+) ions, which represents a major contribution towards understanding the molecular basis of lead poisoning. The MAD data collected at the Pb edge were also used with isomorphous replacement data from the same Pb co-crystal and a Hg co-crystal to provide the first delineation of the enzyme's quaternary structure. In this MADIR analysis, the Hg co-crystal data were treated as native data. Anomalous difference Fouriers were again used, revealing that Hg(2+) had substituted for the same Zn(2+) cofactor ion as had Pb(2+), a finding of fundamental importance for the understanding of mercury poisoning. In addition, Pt(2+) ions were found to bind at the same place in the structure. The refined structures of the Pb- and the Hg-complexed enzymes are presented at 2.5 and 3.0 A resolution, respectively.

PubMed: 10739915
DOI: 10.1107/S0907444900000597

Experimental method

X-RAY DIFFRACTION (3 Å)