Smc3 ChIP fraction
Chromatin immunoprecipitation was carried out as previously described (Katou et al, 2003). DNA from WCE and ChIP fraction were further sheared to the average size of 150bp by ultra sonicator Covaris (Covaris, Inc.), end-repaired, ligated to sequencing adapters and amplified according to manufacturers instructions (Applied Biosystems SOLiD Library Preparation Protocol). Gel-purified amplified DNA between 100 and 150bp was sequenced on the Applied Biosystems Solid 3.5 platform to generate 50-base reads.