of ChIP-exo peaks with a standard deviation of <1 nt, while it is found within ∼25 nt of the center of a traditional ChIP-seq peak. Demonstrating the power of ChIP-exo as a tool for structural biology, comparison of protein-DNA crystal structures with ChIP-exo of the preinitiation complex (Rhee and Pugh 2012) and of the ATP-dependent chromatin remodeler Isw2 (Yen et al. 2012) shows that the pattern of ChIP-exo read starts for TFIIB and for Isw2 successfully identified DNA sites in close proximity to the relevant protein.
