Sequestration of zinc oxide by fimbrial designer chelators.
Type 1 fimbriae are surface organelles of Escherichia coli. By engineering a structural component of the fimbriae, FimH, to display a random peptide library, we were able to isolate metal-chelating bacteria. A library consisting of 4 x 10(7) independent clones was screened for binding to ZnO. Sequences responsible for ZnO adherence were identified, and distinct binding motifs were characterized. The sequences selected exhibited various degrees of affinity and specificity towards ZnO. Competitive binding experiments revealed that the sequences recognized only the oxide form of Zn. Interestingly, one of the inserts exhibited significant homology to a specific sequence in a putative zinc-containing helicase, which suggests that searches such as this one may aid in identifying binding motifs in nature. The zinc-binding bacteria might have a use in detoxification of metal-polluted water.
Kjaergaard
K
K
Department of Microbiology, Technical University of Denmark, DK-2800 Lyngby, Denmark.
Sørensen
J K
JK
Schembri
M A
MA
Klemm
P
P
D018829:Adhesins, Bacterial / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D018830:Adhesins, Escherichia coli; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism*; D004265:DNA Helicases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development; D036781:Fimbriae Proteins; D008969:Molecular Sequence Data; D019151:Peptide Library; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D015034:Zinc Oxide / Q000378:metabolism*
D018829:Adhesins, Bacterial; D018830:Adhesins, Escherichia coli; D001426:Bacterial Proteins; D019151:Peptide Library; C058769:fimH protein, E coli; D036781:Fimbriae Proteins; D004265:DNA Helicases; D015034:Zinc Oxide