A heterotetrameric protein complex that associates with replication origins, where it is required for the initiation of DNA replication, and with replication forks. [ GOC:rn http://www.ncbi.nlm.nih.gov/pubmed/16990792 GOC:rb http://www.ncbi.nlm.nih.gov/pubmed/17467990 http://www.ncbi.nlm.nih.gov/pubmed/12730134 ]
Synonyms: Go, Ichi, Ni and San complex