Analysis of Tus-Ter protein-DNA complexes by Differential Scanning Fluorimetry(DSF) (CAT#: STEM-MB-0778-WXH)

Introduction

Tus is a relatively well characterized protein that binds specifically to 21 bp DNA sequences, called Ter, scattered around the circular chromosome of E. coli to coordinate the termination of DNA replication opposite to oriC. The Tus–Ter complex can only arrest a replisome approaching towards its non-permissive face through the formation of a Tus–Ter-lock (TT-lock), whose action is to tighten the complex, avoiding dissociation of Tus. When the replisome approaches the permissive face of the complex, Tus rapidly dissociates from Ter. The TT-lock is formed when the C·G(6) base pair is broken during DNA unwinding at the non-permissive face of the complex. The unpaired C(6) can then bind into a cytosine-binding pocket at the surface of Tus.