2aj0
Solution structure of apoCadA
OverviewOverview
In bacteria, P1-type ATPases are responsible for resistance to di- and monovalent toxic heavy metals by taking them out of the cell. These ATPases have a cytoplasmic N terminus comprising metal binding domains defined by a betaalphabetabetaalphabeta fold and a CXXC metal binding motif. To check how the structural properties of the metal binding site in the N terminus can influence the metal specificity of the ATPase, the first structure of a Cd(II)-ATPase N terminus was determined by NMR and its coordination sphere was investigated by X-ray absorption spectroscopy. A novel metal binding environment was found, comprising the two conserved Cys residues of the metal binding motif and a Glu in loop 5. A bioinformatic search identifies an ensemble of highly homologous sequences presumably with the same function. Another group of highly homologous sequences is found which can be referred to as zinc-detoxifying P1-type ATPases with the metal binding pattern DCXXC in the N terminus. Because no carboxylate groups participate in Cu(I) or Ag(I) binding sites, we suggest that the acidic residue plays a key role in the coordination properties of divalent cations, hence conferring a function to the N terminus in the metal specificity of the ATPase.
About this StructureAbout this Structure
2AJ0 is a Single protein structure of sequence from Listeria monocytogenes. Full crystallographic information is available from OCA.
ReferenceReference
Structural basis for metal binding specificity: the N-terminal cadmium binding domain of the P1-type ATPase CadA., Banci L, Bertini I, Ciofi-Baffoni S, Su XC, Miras R, Bal N, Mintz E, Catty P, Shokes JE, Scott RA, J Mol Biol. 2006 Feb 24;356(3):638-50. Epub 2005 Dec 5. PMID:16388822 Page seeded by OCA on Sat May 3 19:06:29 2008