The structure of the mer operon.
The DNA sequence has been determined for a 3.8-kb region which encodes the mercury-resistance (mer) operon of the IncFII plasmid NR1. The sequence reveals 4 open reading frames which could encode proteins of 12,522, 9,429, 14,965, and 58,912 d corresponding to the 4 previously described Hg-inducible proteins detected in minicells carrying mer+ plasmids. The Hg(II) reductase protein sequence is about 90% homologous to that of Tn501, but the DNA sequence shows a homology of 60-70% to that of Tn501 except for short regions of very high homology. The entire mer region is 63.4% G-C overall. The region encoding the merR (positive regulatory) function has 3 possible open reading frames, 2 of which overlap in one direction and the third of which reads in the opposite direction. Attempts to visualize the polypeptide(s) encoded by the merR cistron were unsuccessful.
Barrineau
P
P
Gilbert
P
P
Jackson
W J
WJ
Jones
C S
CS
Summers
A O
AO
Wisdom
S
S
D001419:Bacteria / Q000187:drug effects / Q000235:genetics*; D001483:Base Sequence; D004262:DNA Restriction Enzymes; D004352:Drug Resistance, Microbial; D005798:Genes, Bacterial; D008628:Mercury / Q000494:pharmacology*; D009876:Operon; D010641:Phenotype; D011815:R Factors
D004262:DNA Restriction Enzymes; D008628:Mercury