Replication terminator protein of Escherichia coli is a transcriptional repressor of its own synthesis.

AUTOR(ES)

Natarajan, S

RESUMO

We have investigated the regulation of synthesis of the replication terminator protein (Ter) of Escherichia coli and have discovered that the protein is a repressor of its own synthesis at the transcriptional step. Since the synthesis of Ter protein was observed to be down-regulated in vivo, these results are consistent with autoregulation as one control mechanism of Ter protein within the cell. Analysis of the tus gene that encodes the Ter protein revealed that transcription was initiated from a single promoter located within the upstream nontranscribed sequence. In vitro footprinting experiments have revealed that Ter protein prevented binding of RNA polymerase to the promoter sequence when both proteins were incubated with promoter DNA. However, once bound to the promoter, RNA polymerase could not be displaced by Ter protein. Conversely, prebound Ter protein could not be dislodged from its binding site at the promoter when challenged with RNA polymerase. Therefore, Ter protein can serve as a transcriptional repressor of its own synthesis by preventing RNA polymerase from binding to the tus promoter when both proteins are present in the cell milieu.

Documentos Relacionados

• The replication initiator protein of plasmid pSC101 is a transcriptional repressor of its own cistron.
• Replication initiator protein of plasmid R6K autoregulates its own synthesis at the transcriptional step.
• Membrane-bound deoxyribonucleic acid from Escherichia coli: effects of replication, protein synthesis, and ribonucleic acid synthesis.
• Activity of a Streptomyces transcriptional terminator in Escherichia coli.
• Mutations that affect phosphorylation of the adenovirus DNA-binding protein alter its ability to enhance its own synthesis.