title: Polypeptides encoded by the mer operon.
abstract: HgCl2-induced polypeptides synthesized by Escherichia coli minicells containing recombinant or natural HgR plasmids were labeled with [35S]methionine and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. All plasmids examined encoded two heavily labeled, HgCl2-inducible polypeptides of 69,000 and 12,000 daltons. Most plasmids also encoded two additional HgCl2-inducible proteins in the 14,000- to 17,000-dalton range. Antiserum prepared against a purified mercuric ion reductase reacts with the 69,000-dalton polypeptide and a minor 66,000-dalton protein seen in several different HgR minicells. Recombinant plasmids constructed from portions of mer DNA from the IncFII plasmid NR1 were also analyzed in the minicell system. Five HgCl2-inducible polypeptides (69,000, 66,000, 15,100, 14,000, and 12,000 daltons) were synthesized in minicells carrying pRR130, a recombinant derivative containing the EcoRI-H and EcoRI-I restriction fragments of NR1. The EcoRI-H fragment of NR1 encodes the three small mer proteins of 15,100, 14,000, and 12,000 daltons and the amino-terminal 40,000 daltons of the mercuric ion reductase monomer.
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D015246:Deoxyribonuclease EcoRI; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D008628:Mercury / Q000494:pharmacology*; D008970:Molecular Weight; D009876:Operon; D010088:Oxidoreductases / Q000235:genetics*; D011815:R Factors
chemical_list: D001426:Bacterial Proteins; D010088:Oxidoreductases; C021551:mercuric reductase; D004262:DNA Restriction Enzymes; D015246:Deoxyribonuclease EcoRI; D008628:Mercury