scholarly journals Base insertion and deletion mutations induced in an Escherichia coli plasmid by benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide.

1981 ◽  
Vol 78 (11) ◽  
pp. 6817-6820 ◽  
Author(s):  
H. Mizusawa ◽  
C. H. Lee ◽  
T. Kakefuda ◽  
K. McKenney ◽  
H. Shimatake ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Deletion Mutations ◽  
Insertion And Deletion ◽  
Coli Plasmid ◽  
Base Insertion

The lacI Gene as a Target for Mutation in Transgenic Rodents and Escherichia coli

Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1441-1451
Author(s):  
Johan G de Boer ◽  
Barry W Glickman
Keyword(s):  
Escherichia Coli ◽  
Dna Repair ◽  
Dna Binding ◽  
Transgenic Animals ◽  
Single Copy ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Large Database ◽  
Deletion Mutations ◽  
Laci Gene

Abstract The lacI gene has been used extensively for the recovery and analysis of mutations in bacteria with various DNA repair backgrounds and after exposure to a wide variety of mutagens. This has resulted in a large database of information on mutational mechanisms and specificity of many mutagens, as well as the effect of DNA repair background on mutagenicity. Most importantly, knowledge about the mutational sensitivity of the lacI gene is now available, yielding information about mutable nucleotides. This popularity and available knowledge resulted in the use of the lacI gene in transgenic rodents for the study of mutagenesis in mammals, where it resides in ~40 repeated copies. As the number of sequenced mutations recovered from these animals increases, we are able to analyze the sites at which mutations have been recovered in great detail and to compare the recovered sites between bacteria and transgenic animals. The nucleotides that code for the DNA-binding domain are nearly saturated with base substitutions. Even after determining the sequences of ~10,000 mutations recovered from the animals, however, new sites and new changes are still being recovered. In addition, we compare the nature of deletion mutations between bacteria and animals. Based on the nature of deletions in the animals, we conclude that each deletion occurs in a single copy of the gene.

scholarly journals Effects of DNA heterologies on bacteriophage lambda recombination.

Genetics ◽  
1988 ◽  
Vol 118 (1) ◽  
pp. 13-19
Author(s):  
R K Pearson ◽  
M S Fox
Keyword(s):  
Bacteriophage Lambda ◽  
Indirect Evidence ◽  
Direct Products ◽  
Base Pairs ◽  
Heteroduplex Dna ◽  
Deletion Mutations ◽  
Genetic Crosses ◽  
Insertion And Deletion ◽  
Progeny Phage ◽  
Substitution Mutation

Abstract Previous studies of bacteriophage lambda recombination have provided indirect evidence that substantial sequence nonhomologies, such as insertions and deletions, may be included in regions of heteroduplex DNA. However, the direct products of heterology-containing heteroduplex DNA--heterozygous progeny phage--have not been observed. We have constructed a series of small insertion and deletion mutations in the cI gene to examine the possibility that small heterologies might be accommodated in heterozygous progeny phage. Genetic crosses were carried out between lambda cI- Oam29 and lambda cI+ Pam80 under replication-restricted conditions. Recombinant O+P+ progeny were selected on mutL hosts and tested for cI heterozygosity. Heterozygous recombinants were readily observed with crosses involving insertions of 4 to 19 base pairs (bp) in the cI gene. Thus, nonhomologies of at least 19 bp can be accommodated in regions of heteroduplex DNA during lambda recombination. In contrast, when a cI insertion or deletion mutation of 26 bp was present, few of the selected recombinants were heterozygous for cI. Results using a substitution mutation, involving a 26-bp deletion with a 22-bp insertion, suggest that the low recovery of cI heterozygotes containing heterologies of 26 bp or more is due to a failure to encapsulate DNA containing heterologies of 26 bp or more into viable phage particles.

Nucleotide sequence of the partition locus of Escherichia coli plasmid pSC101

Gene ◽  
1983 ◽  
Vol 24 (2-3) ◽  
pp. 309-315 ◽  
Author(s):  
Christine A. Miller ◽  
William T. Tucker ◽  
Peter A. Meacock ◽  
Petter Gustaf sson ◽  
Stanley N. Cohen
Keyword(s):  
Escherichia Coli ◽  
Nucleotide Sequence ◽  
Coli Plasmid

scholarly journals CMY-13, a Novel Inducible Cephalosporinase Encoded by an Escherichia coli Plasmid

2004 ◽  
Vol 48 (8) ◽  
pp. 3172-3174 ◽  
Author(s):  
V. Miriagou ◽  
L. S. Tzouvelekis ◽  
L. Villa ◽  
E. Lebessi ◽  
A. C. Vatopoulos ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Citrobacter Freundii ◽  
Coli Plasmid

ABSTRACT An IncN plasmid (p541) from Escherichia coli carried a Citrobacter freundii-derived sequence of 4,252 bp which included an ampC-ampR region and was bound by two directly repeated IS26 elements. ampC encoded a novel cephalosporinase (CMY-13) with activity similar to that of CMY-2. AmpR was likely functional as indicated in induction experiments.

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