What is all this fuss about Tus? Comparison of recent findings from biophysical and biochemical experiments.
Crit Rev Biochem Mol Biol
; 53(1): 49-63, 2018 02.
Article
em En
| MEDLINE
| ID: mdl-29108427
ABSTRACT
Synchronizing the convergence of the two-oppositely moving DNA replication machineries at specific termination sites is a tightly coordinated process in bacteria. In Escherichia coli, a "replication fork trap" - found within a chromosomal region where forks are allowed to enter but not leave - is set by the protein-DNA roadblock Tus-Ter. The exact sequence of events by which Tus-Ter blocks replisomes approaching from one direction but not the other has been the subject of controversy for many decades. Specific protein-protein interactions between the nonpermissive face of Tus and the approaching helicase were challenged by biochemical and structural studies. These studies show that it is the helicase-induced strand separation that triggers the formation of new Tus-Ter interactions at the nonpermissive face - interactions that result in a highly stable "locked" complex. This controversy recently gained renewed attention as three single-molecule-based studies scrutinized this elusive Tus-Ter mechanism - leading to new findings and refinement of existing models, but also generating new questions. Here, we discuss and compare the findings of each of the single-molecule studies to find their common ground, pinpoint the crucial differences that remain, and push the understanding of this bipartite DNA-protein system further.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA Bacteriano
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Proteínas de Escherichia coli
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Proteínas de Ligação a DNA
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Replicação do DNA
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Escherichia coli
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article