Bacterial Replication Termination: Difference between revisions
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<StructureSection load='2ewj' size='350' side='right' scene='Bacterial_Replication_Termination/Tus_opening/1' caption='E. coli TER-binding protein complex with DNA (PDB code [[2ewj]])'> | <StructureSection load='2ewj' size='350' side='right' scene='Bacterial_Replication_Termination/Tus_opening/1' caption='E. coli TER-binding protein complex with DNA and I- ion (purple) (PDB code [[2ewj]])'> | ||
In most bacterial DNA replication, initiation occurs at an origin where, due to the circular nature of the chromosome, the replication forks move bidirectionally to end at approximately 180 degrees away, at a specific sequence termini region [1]. Bacterial replication termination systems have been well studied in ''Eschericia coli'' and ''Bascillus subtilis''. In both systems a ''trans''-acting replication termination protein binds to a specific ''cis''-acting DNA sequences; the replication termini (''ter''), and the DNA-protein complex arrests the progression of replication forks [2]. The terminator sites are orientated so that protein binding is asymmetric, allowing the complexes to block the replication machinery from only one direction while letting them proceed unimpeded from the other direction [1]. In this way they are said to act in a polar manner. The proteins involved in this termination are non-homologous and differ structurally in ''E.coli'' and ''B.subtilis'', although each contains similar contrahelicase activity and performs similar functions in arresting replication [1]. | In most bacterial DNA replication, initiation occurs at an origin where, due to the circular nature of the chromosome, the replication forks move bidirectionally to end at approximately 180 degrees away, at a specific sequence termini region [1]. Bacterial replication termination systems have been well studied in ''Eschericia coli'' and ''Bascillus subtilis''. In both systems a ''trans''-acting replication termination protein binds to a specific ''cis''-acting DNA sequences; the replication termini (''ter''), and the DNA-protein complex arrests the progression of replication forks [2]. The terminator sites are orientated so that protein binding is asymmetric, allowing the complexes to block the replication machinery from only one direction while letting them proceed unimpeded from the other direction [1]. In this way they are said to act in a polar manner. The proteins involved in this termination are non-homologous and differ structurally in ''E.coli'' and ''B.subtilis'', although each contains similar contrahelicase activity and performs similar functions in arresting replication [1]. | ||
