1qnv
From Proteopedia
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| , resolution 2.5Å | |||||||
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| Sites: | |||||||
| Ligands: | |||||||
| Activity: | Porphobilinogen synthase, with EC number 4.2.1.24 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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. This structure supersedes the now removed PDB entry 1QMK. 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
Page seeded by OCA on Sun Mar 30 23:16:30 2008
