Tus prevents overreplication of oriC plasmid DNA Journal Article


Authors: Hiasa, H.; Marians, K. J.
Article Title: Tus prevents overreplication of oriC plasmid DNA
Abstract: Minichromosome plasmid DNA templates containing oriC and two Ter sites, oriented as they are on the Escherichia coli chromosome, have been used to study the role of Tus in termination of bidirectional replication. In replication reactions reconstituted with purified proteins where it could be demonstrated that each active template was replicating bidirectionally, Tus was required to prevent extensive overreplication. In the presence of Tus, both replication forks terminated DNA synthesis at one or the other Ter site in an apparent stepwise manner. First, the progress of one replication fork was arrested by a properly oriented Tus-Ter complex. Then, either because of steric hindrance resulting from the stalled replication machinery of the first fork or because of the formation of a branched DNA structure, the progression of the second opposing fork was halted at the same site on the DNA template. In the absence of Tus, overreplication required DNA ligase and arose via a template strand-switching mechanism. Thus, the role of Tus in E. coli is more likely to prevent overreplication rather than to ensure accurate termination.
Keywords: dna-binding proteins; dna replication; dna synthesis; bacterial proteins; dna; isotope labeling; escherichia coli; plasmids; models, genetic; dna structure; nucleic acid conformation; structure analysis; electrophoresis, gel, two-dimensional; chromosomes, bacterial; dna ligases; transcription termination; dna template; regulator gene; replication origin; deoxyribonucleases, type ii site-specific; minichromosome; priority journal; article; support, u.s. gov't, p.h.s.
Journal Title: Journal of Biological Chemistry
Volume: 269
Issue: 43
ISSN: 0021-9258
Publisher: American Society for Biochemistry and Molecular Biology  
Date Published: 1994-10-28
Start Page: 26959
End Page: 26968
Language: English
PROVIDER: scopus
PUBMED: 7929435
DOI/URL:
Notes: Export Date: 14 January 2019 -- Article -- Source: Scopus
Citation Impact
MSK Authors
  1. Kenneth Marians
    138 Marians
  2. Hiroshi   Hiasa
    21 Hiasa