Spo0A, the key transcriptional regulator for entrance into sporulation, is an inhibitor of DNA replication.
The transcription factor Spo0A is a master regulator for entry into sporulation in Bacillus subtilis and also regulates expression of the virulent B. subtilis phage phi29. Here, we describe a novel function for Spo0A, being an inhibitor of DNA replication of both, the phi29 genome and the B. subtilis chromosome. Binding of Spo0A near the phi29 DNA ends, constituting the two origins of replication of the linear phi29 genome, prevents formation of phi29 protein p6-nucleoprotein initiation complex resulting in inhibition of phi29 DNA replication. At the B. subtilis oriC, binding of Spo0A to specific sequences, which mostly coincide with DnaA-binding sites, prevents open complex formation. Thus, by binding to the origins of replication, Spo0A prevents the initiation step of DNA replication of either genome. The implications of this novel role of Spo0A for phage phi29 development and the bacterial chromosome replication during the onset of sporulation are discussed.
Castilla-Llorente
Virginia
V
Instituto de Biología Molecular Eladio Viñuela (CSIC), Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma, Canto Blanco, Madrid, Spain.
Muñoz-Espín
Daniel
D
Villar
Laurentino
L
Salas
Margarita
M
Meijer
Wilfried J J
WJ
D017103:Bacillus Phages / Q000235:genetics; D001412:Bacillus subtilis / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology*; D001483:Base Sequence; D002876:Chromosomes, Bacterial / Q000235:genetics; D004261:DNA Replication; D004269:DNA, Bacterial / Q000502:physiology; D004279:DNA, Viral / Q000502:physiology; D004268:DNA-Binding Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D051738:Origin Recognition Complex / Q000378:metabolism; D011485:Protein Binding; D013171:Spores, Bacterial / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology*; D015533:Transcriptional Activation
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004279:DNA, Viral; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; C114650:OriC chromosomal replication origin; D051738:Origin Recognition Complex; C080950:Spo0A protein, Bacillus subtilis; D014157:Transcription Factors