A DNA methylation ratchet governs progression through a bacterial cell cycle.

Détails

ID Serval
serval:BIB_5B5ECD640E6D
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
A DNA methylation ratchet governs progression through a bacterial cell cycle.
Périodique
Proceedings of the National Academy of Sciences of the United States of America
Auteur⸱e⸱s
Collier J., McAdams H.H., Shapiro L.
ISSN
0027-8424
Statut éditorial
Publié
Date de publication
2007
Peer-reviewed
Oui
Volume
104
Numéro
43
Pages
17111-17116
Langue
anglais
Résumé
The Caulobacter cell cycle is driven by a cascade of transient regulators, starting with the expression of DnaA in G(1) and ending with the expression of the essential CcrM DNA methyltransferase at the completion of DNA replication. The timing of DnaA accumulation was found to be regulated by the methylation state of the dnaA promoter, which in turn depends on the chromosomal position of dnaA near the origin of replication and restriction of CcrM synthesis to the end of the cell cycle. The dnaA gene is preferentially transcribed from a fully methylated promoter. DnaA initiates DNA replication and activates the transcription of the next cell-cycle regulator, GcrA. With the passage of the replication fork, the dnaA promoter becomes hemimethylated, and DnaA accumulation drops. GcrA then activates the transcription of the next cell-cycle regulator, CtrA, once the replication fork passes through the ctrA P1 promoter, generating two hemimethylated copies of ctrA. The ctrA gene is preferentially transcribed from a hemimethylated promoter. CtrA then activates the transcription of ccrM, to bring the newly replicated chromosome to the fully methylated state, promoting dnaA transcription and the start of a new cell cycle. We show that the cell-cycle timing of CcrM is critical for Caulobacter fitness. The sequential changes in the chromosomal methylation state serve to couple the progression of DNA replication to cell-cycle events regulated by the master transcriptional regulatory cascade, thus providing a ratchet mechanism for robust cell-cycle control.
Mots-clé
Bacterial Proteins, Base Sequence, Caulobacter, Cell Cycle, DNA Methylation, DNA-Binding Proteins, Molecular Sequence Data, Promoter Regions, Genetic, Site-Specific DNA-Methyltransferase (Adenine-Specific), Time Factors, Transcription, Genetic
Pubmed
Web of science
Open Access
Oui
Création de la notice
27/02/2009 15:42
Dernière modification de la notice
20/08/2019 14:14
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