PMID- 2853392
OWN - NLM
STAT- MEDLINE
DCOM- 19890503
LR  - 20191022
IS  - 0147-619X (Print)
IS  - 0147-619X (Linking)
VI  - 20
IP  - 2
DP  - 1988 Sep
TI  - The distribution and divergence of DNA sequences related to the Tn21 and Tn501 
      mer operons.
PG  - 127-36
AB  - The mercury resistance (mer) operons of the Gram-negative bacterial transposons, 
      Tn21 and Tn501, are phenotypically indistinguishable and have extensive DNA 
      identity. However, Tn21 mer has an additional coding region (merC) in the middle 
      of the operon which is lacking in Tn501 and there is also a discrete region of 
      the mercuric ion reductase gene (merA) which differs markedly between the two 
      operons. DNA fragment probes were used to determine the distribution of specific 
      mer coding regions in two distinct collections of mercury-resistant (Hgr) 
      Gram-negative bacteria. Colony blot hybridization analysis showed that 
      merC-positive operons occur almost exclusively in Escherichia, although 
      merC-negative operons can also be found in this genus. The merC-negative operons 
      were found in Citrobacter, Klebsiella, and Enterobacter and in some Pseudomonas. 
      Most of the Pseudomonas did not hybridize detectably with either of the two 
      operons studied, indicating that they harbor an unrelated or more distantly 
      related class of mercury resistance locus. Southern hybridization patterns 
      demonstrated that the merC-positive mer operon is well conserved at the DNA 
      level, whereas the merC-negative operons are much less conserved. The presence of 
      merC also correlated with conservation of a specific variant region of the merA 
      gene and with an antibiotic resistance pattern similar to that of Tn21. Tn501 
      appears to be an atypical example of the merC-negative subgroup of Hgr loci.
FAU - Gilbert, M P
AU  - Gilbert MP
AD  - Department of Microbiology, University of Georgia, Athens 30602.
FAU - Summers, A O
AU  - Summers AO
LA  - eng
GR  - AI-19221/AI/NIAID NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Plasmid
JT  - Plasmid
JID - 7802221
RN  - 0 (DNA Transposable Elements)
RN  - 0 (DNA, Bacterial)
RN  - FXS1BY2PGL (Mercury)
SB  - IM
MH  - Blotting, Southern
MH  - *DNA Transposable Elements
MH  - DNA, Bacterial/genetics
MH  - Drug Resistance, Microbial/genetics
MH  - Escherichia coli/drug effects/*genetics
MH  - Gram-Negative Bacteria/drug effects/*genetics
MH  - Mercury/*pharmacology
MH  - Nucleic Acid Hybridization
MH  - *Operon
MH  - R Factors
MH  - Restriction Mapping
MH  - Species Specificity
EDAT- 1988/09/01 00:00
MHDA- 1988/09/01 00:01
CRDT- 1988/09/01 00:00
PHST- 1988/09/01 00:00 [pubmed]
PHST- 1988/09/01 00:01 [medline]
PHST- 1988/09/01 00:00 [entrez]
AID - 0147-619X(88)90015-7 [pii]
AID - 10.1016/0147-619x(88)90015-7 [doi]
PST - ppublish
SO  - Plasmid. 1988 Sep;20(2):127-36. doi: 10.1016/0147-619x(88)90015-7.