Author:
Kuempel P,Høgaard A,Nielsen M,Nagappan O,Tecklenburg M
Abstract
The dif locus is a RecA-independent recombination site, located in the terminus region of the chromosome of Escherichia coli. This site functions to reduce circular dimer chromosomes to monomers before cell division. Strains lacking this site exhibit the Dif phenotype, in which a fraction of the cells form extended filaments with abnormal nucleoids, and the SOS system is induced. We have used a transposon (Tndif), as well as linear transformation, to position dif in 19 locations around the chromosome. All of the suppressing insertions that we obtained were within 10 kb of the normal site, even in strains in which the normal symmetry, between the origin of replication and dif had been altered by 200 kb. We also observed that the nonsuppressing insertions in the terminus region became suppressing if a deletion occurred that extended from the ectopic site up to or past the normal location of dif. We propose that dif is normally located at the center of converging polarities in the terminus region and that deletions that restore suppression do so by placing ectopic sites once again at the center of this polarity. Similar results and conclusions are described in this issue.
Publisher
Cold Spring Harbor Laboratory
Subject
Developmental Biology,Genetics
Reference28 articles.
1. Ausubel, F., R. Brent, R.E. Kingston, D.D. Moore, J.G. Seidman, J.A. Smith, and K. Struhl, eds. 1987. Current protocols in molecular biology. Wiley Interscience, New York, NY.
2. Structure and organization of hip, an operon that affects lethality due to inhibition of peptidoglycan or DNA synthesis.;J. Bacteriol.,1991
3. Escherichia coli XerC recombinase is required for chromosomal segregation at cell division.;New Biol.,1991
4. Two related recombinases are required for site-specific recombination at dif and cer in E. coli K12
5. Positive selection for loss of tetracycline resistance.;J. Bacteriol.,1980
Cited by
42 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献