Nuclear matrix–DNA complex resulting fromEcoR1 digestion of HeLa nucleoids is enriched for DNA replicating forks

Abstract
Upon treatment of HeLa nucleoids with EcoR1 restriction enzyme, a minute fraction of the DNA remains attached to the nuclear matrix. This matrix-DNA complex appears to be composed of a unique set of proteins. Electron microscopic analysis of the DNA fragments present shows an enrichment for HeLa DNA replicating forks.Images