Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Editor

Personal info

View

About

Terms

Javascript disabled

Please enable Javascript support in your browser to use this application.

Instructions on how to enable JavaScript on different browsers can be found here: http://www.google.com/support/bin/answer.py?answer=23852.

[edit this page]

Xiao, Z. et al.

Xiao, Loughlin, George, Howlett, Wedd,

C-terminal domain of the membrane copper transporter Ctr1 from Saccharomyces cerevisiae binds four Cu(I) ions as a cuprous-thiolate polynuclear cluster: sub-femtomolar Cu(I) affinity of three proteins involved in copper trafficking.

The cytosolic C-terminal domain of the membrane copper transporter Ctr1 from the yeast Saccharomyces cerevisiae, Ctr1c, was expressed in E. coli as an oxygen-sensitive soluble protein with no significant secondary structure. Visible-UV spectroscopy demonstrated that Ctr1c bound four Cu(I) ions, structurally identified as a Cu(I)(4)(micro-S-Cys)(6) cluster by Xray absorption spectroscopy. This was the only metalated form detected by electrospray ionization mass spectrometry. An average dissociation constant K(D) = (K(1)K(2)K(3)K(4))(1/4) = 10(-)(19) for binding of Cu(I) to Ctr1c was estimated via competition with the ligand bathocuproine disulfonate bcs (beta(2) = 10(19.8)). Equivalent experiments for the yeast chaperone Atx1 and an N-terminal domain of the yeast Golgi pump Ccc2, which both bind a single Cu(I) ion, provided similar K(D) values. The estimates of K(D) were supported by independent estimates of the equilibrium constants K(ex) for exchange of Cu(I) between pairs of these three proteins. It is apparent that, in vitro, the three proteins buffer "free" Cu(I) concentrations in a narrow range around 10(-)(19) M. The results provide quantitative support for the proposals that, in yeast, (a) "free" copper concentrations are very low in the cytosol and (b) the Cu(I) trafficking gradient is shallow along the putative Ctrlc --> Atx1 --> Ccc2n metabolic pathway. In addition, both Ctr1c and its copper-responsive transcription factor Mac1 contain similar clusters which may be important in signaling copper status in yeast.[1]

References

C-terminal domain of the membrane copper transporter Ctr1 from Saccharomyces cerevisiae binds four Cu(I) ions as a cuprous-thiolate polynuclear cluster: sub-femtomolar Cu(I) affinity of three proteins involved in copper trafficking. Xiao, Z., Loughlin, F., George, G.N., Howlett, G.J., Wedd, A.G. J. Am. Chem. Soc. (2004) [Pubmed]

Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenes Open Access Licence Privacy Policy Terms of Use apsburg

The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.