DNA replication origin

Replication origin is the sequences where replication started. Usually, DNA structure is the double helix, to be used as the template for replication, the duplex parental strands must be opened, by breaking hydrogen bonds between two strands. Therefore, usually, replication origin is the A-T rich sequences, as A-T base pairs contain fewer hydrogen bond than G-C base pairs. In E. coli, there is only a single origin for genome replication called OriC (232 – 245 bp). The initiator proteins bind this sequence and start replication in Continue Reading →

Collisions between the replisome and a transcribing RNA polymerase

It is widely reported that DNA replication progression is effected by many factors such as DNA damage, lesion or protein, acid nucleic … , that can lead to fork arrest or sometimes fork collapse. Depending on the situation, cell have different pathways to rescue fork progression or post-replication pathways to faithfully maintain genetic information such as DNA repair …. In the cell, it’s highly possible that RNA transcription can occur simultaneously with DNA replication. In this case, the collision between replisome and transcription complex is unavoidable. Continue Reading →