Structure and Function of the Escherichia coli SeqA Protein

Abstract: The SeqA protein is a negative factor for initiation of chromosomal replication in Escherichia coli.In vivo the SeqA molecules are found in a form of tetramer or multimers. The SeqA protein has the N-terminal aggregation and the C-terminal DNA-binding domains. The E. coli chromosomal origin for replication (oriC) contains 11 GATC sites and newly replicated oriC is hemimethylated. The site of two neighboured hemimethylated GATC is the best target of SeqA for binding. SeqA binds to hemimthylated GATC to prevent re-initiation of replication， namely the sequestration of oriC. Sequestration is one of the mechanisms to make sure that each origin is initiated only onceper cell cycle. The SeqA protein is not only a regulatory factor for replication initiation but also a transcription factor， inhibiting or activating expression of some genes. In the paper， we reviewed the character of structural and functional domain of SeqA， and its roles in control for initiation of DNA replication， gene expression and cell division.

CSTR: 32200.14.cjcb.2016.06.0010