Required for establishment of sister chromatid cohesion during S phase but not for its further maintenance during G2 or M phases or for loading the cohesin complex onto DNA. Interacts with the three known alternate replication factor C (RFC) complexes; suggesting that these complexes have essential but redundant activity in cohesion establishment. Acts by acetylating the cohesin complex component SMC3. In vitro; possesses acetyltransferase activity where it can acetylate itself and components of the cohesin complex (MCD1; IRR1 and PDS5); but is unable to acetylate histones. {ECO:0000269|PubMed:12665596; ECO:0000269|PubMed:15668154; ECO:0000269|PubMed:9990855; ECO:0000269|PubMed:9990856}.