Monday, July 17, 2006
Berkely, California: The molecular machinery that starts the process by which a biological cell divides into two identical daughter cells apparently worked so well early on that evolution has conserved it across the eons in all forms of life on Earth. Researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory and the University of California at Berkeley have shown that the core machinery for initiating DNA replication is the same for all three domains of life - Archaea, Bacteria and Eukarya.
In two papers that will be concurrently published in the August edition of the journal Nature Structural and Molecular Biology (now available on-line), the researchers report the identification of a helical substructure within a superfamily of proteins, called AAA+, as the molecular "initiator" of DNA replication in a bacteria, Escherichia coli (E. coli), and in a eukaryote, Drosophila melanogaster, the fruit fly. Taken with earlier research that identified AAA+ proteins at the heart of the DNA replication initiator in archaea organisms, these new findings indicate that DNA replication is an ancient event that evolved millions of years ago, prior to when Archae, Bacteria and Eukarya split into separate domains of life.