For the first time, an elusive step in the process of human
DNA replication has been demystified by scientists at Penn State University.
According to senior author Stephen J. Benkovic, an Evan Pugh Professor of
Chemistry and Holder of the Eberly Family Chair in Chemistry at Penn State, the
scientists "discovered how a key step in human DNA replication is
performed." The results of the research will be published in the journal
eLife on 2 April 2013.
Part of the DNA replication process -- in humans and in
other life forms -- involves loading of molecular structures called sliding
clamps onto DNA. This crucial step in DNA replication had remained somewhat
mysterious and had not been well studied in human DNA replication. Mark
Hedglin, a post-doctoral researcher in Penn State's Department of Chemistry and
a member of Benkovic's team, explained that the sliding clamp is a ring-shaped protein
that acts to encircle the DNA strand, latching around it like a watch band. The
sliding clamp then serves to anchor special enzymes called polymerases to the
DNA, ensuring efficient copying of the genetic material.