title: Cyanobacterial metallothionein gene expressed in Escherichia coli. Metal-binding properties of the expressed protein.
abstract: The recently isolated Synechococcus gene smtA encodes the only characterised prokaryotic protein designated to be a metallothionein (MT). To examine the metal-binding properties of its product the smtA gene was expressed in Escherichia coli as a carboxyterminal extension of glutathione-S-transferase. The pH of half dissociation of Zn, Cd and Cu ions from the expressed protein was determined to be 4.10, 3.50, 2.35, respectively, indicating a high affinity for these ions (in particular for Zn in comparison to mammalian MT). E. coli expressing this gene showed enhanced (ca. 3-fold) accumulation of Zn.
authors.affiliation: Department of Biological Sciences, University of Durham, UK.
authors.forename: J
authors.initials: J
authors.lastname: Shi
authors.forename: W P
authors.initials: WP
authors.lastname: Lindsay
authors.forename: J W
authors.initials: JW
authors.lastname: Huckle
authors.forename: A P
authors.initials: AP
authors.lastname: Morby
authors.forename: N J
authors.initials: NJ
authors.lastname: Robinson
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D000458:Cyanobacteria / Q000235:genetics*; D004269:DNA, Bacterial; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D008668:Metallothionein / Q000235:genetics* / Q000378:metabolism; D008670:Metals / Q000378:metabolism; D008969:Molecular Sequence Data
chemical_list: D004269:DNA, Bacterial; D008670:Metals; D008668:Metallothionein