1qnv
From Proteopedia
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YEAST 5-AMINOLAEVULINIC ACID DEHYDRATASE LEAD (PB) COMPLEX
Overview
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.
About this Structure
1QNV is a Single protein structure of sequence from Saccharomyces cerevisiae with PB as ligand. This structure superseeds the now removed PDB entry 1QMK. Active as Porphobilinogen synthase, with EC number 4.2.1.24 Structure known Active Site: CAT. Full crystallographic information is available from OCA.
Reference
MAD analyses of yeast 5-aminolaevulinate dehydratase: their use in structure determination and in defining the metal-binding sites., Erskine PT, Duke EM, Tickle IJ, Senior NM, Warren MJ, Cooper JB, Acta Crystallogr D Biol Crystallogr. 2000 Apr;56(Pt 4):421-30. PMID:10739915
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