Functional analysis of the Escherichia coli zinc transporter ZitB.
The membrane transporter ZitB responsible for Zn(II) efflux in Escherichia coli was studied by site-directed mutagenesis to elucidate the function of individual amino acid residues. Substitutions of several charged or polar residues, H53, H159, D163 and D186, located in predicted transmembrane domains resulted in loss of ZitB function. In contrast, neither the amino-terminal nor the carboxy-terminal regions, both histidine-rich, were required for function.
Lee
Sun Mi
SM
Department of Soil, Water, and Environmental Science, University of Arizona, Shantz Bld #38 Rm 424, Tucson 85721, USA.
Grass
Gregor
G
Haney
Christopher J
CJ
Fan
Bin
B
Rosen
Barry P
BP
Anton
Andreas
A
Nies
Dietrich H
DH
Rensing
Christopher
C
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D015032:Zinc / Q000378:metabolism*
D002352:Carrier Proteins; C017800:zinc-binding protein; D015032:Zinc