JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Anton, A.
Right arrow Articles by Nies, D. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Anton, A.
Right arrow Articles by Nies, D. H.

 Previous Article  |  Next Article 

Journal of Bacteriology, November 2004, p. 7499-7507, Vol. 186, No. 22
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.22.7499-7507.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Characteristics of Zinc Transport by Two Bacterial Cation Diffusion Facilitators from Ralstonia metallidurans CH34 and Escherichia coli

Andreas Anton,1,{dagger} Annett Weltrowski,1,{dagger} Christopher J. Haney,2,{dagger} Sylvia Franke,2 Gregor Grass,1 Christopher Rensing,2 and Dietrich H. Nies1*

Institut für Mikrobiologie, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany,1 Department of Soil, Water, and Environmental Science, University of Arizona, Tucson, Arizona2

Received 19 March 2004/ Accepted 23 July 2004

CzcD from Ralstonia metallidurans and ZitB from Escherichia coli are prototypes of bacterial members of the cation diffusion facilitator (CDF) protein family. Expression of the czcD gene in an E. coli mutant strain devoid of zitB and the gene for the zinc-transporting P-type ATPase zntA rendered this strain more zinc resistant and caused decreased accumulation of zinc. CzcD, purified as an amino-terminal streptavidin-tagged protein, bound Zn2+, Co2+, Cu2+, and Ni2+ but not Mg2+, Mn2+, or Cd2+, as shown by metal affinity chromatography. Histidine residues were involved in the binding of 2 to 3 mol of Zn2+ per mol of CzcD. ZitB transported 65Zn2+ in the presence of NADH into everted membrane vesicles with an apparent Km of 1.4 µM and a Vmax of 0.57 nmol of Zn2+ min–1 mg of protein–1. Conserved amino acyl residues that might be involved in binding and transport of zinc were mutated in CzcD and/or ZitB, and the influence on Zn2+ resistance was studied. Charged or polar amino acyl residues that were located within or adjacent to membrane-spanning regions of the proteins were essential for the full function of the proteins. Probably, these amino acyl residues constituted a pathway required for export of the heavy metal cations or for import of counter-flowing protons.


* Corresponding author. Mailing address: Institut für Mikrobiologie, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Str. 3, 06099 Halle, Germany. Phone: (49)-345-5526352. Fax: (49)-345-5527010. E-mail: d.nies{at}mikrobiologie.uni-halle.de.

{dagger} A.A., A.W., and C.J.H. contributed equally to this study.


Journal of Bacteriology, November 2004, p. 7499-7507, Vol. 186, No. 22
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.22.7499-7507.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2004 by the American Society for Microbiology. All rights reserved.