Researchers provide atomic view of a histone chaperone

March 1, 2012

Mayo Clinic researchers have gained insights into the function of a member of a family of specialized proteins called histone chaperones. Using nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography, they have determined the 3-D structure and interactions of the histone chaperone Rtt106 down to the atomic details. The findings are published in the journal Nature.

"The interactions we described are important for gene silencing and the ," says senior author Georges Mer, Ph.D., a Mayo Clinic structural biologist. "This is exciting because our newfound knowledge will help us better understand these fundamental ."

In cells, our DNA is part of a structure called chromatin, comprised of proteins, the majority called histones, which are wrapped with the DNA. Associated with the histones is another group of proteins called histone chaperones, which promote the proper assembly or disassembly of the chromatin during the times our DNA is replicated or repaired when damaged. Their dysfunction has been linked to cancer, aging and other diseases.

The Discovery

Before this Mayo study, scientists knew that the histone chaperone Rtt106 helped in the deposition of histones -- specifically, a complex of histones H3 and H4 -- onto the replicating DNA. They did not understand how Rtt106 does this, given that it does not possess any of the known requirements. Histone H3 is in a modified form where one of its , lysine 56, is acetylated. Rtt106 does not seem to have an acetylated lysine reader domain.

Mayo researchers discovered two novel domains in Rtt106 that take on this role. One, termed the homodimerization domain, allows two molecules of Rtt106 to be linked so they can cooperate in binding H3 and H4. The other, called the double PH domain, is responsible for sensing the acetylated lysine of H3 and further reinforces the interaction. The combined actions of the two domains of Rtt106 enable it to perform the chaperoning function efficiently and properly. This is the first time anyone has described this mode of specific association between a histone and a modified histone complex.

Explore further: Core tenets of the 'histone code' are universal

Related Stories

Core tenets of the 'histone code' are universal

September 6, 2007

In one of biology’s most impressive engineering feats, specialized proteins called histones package some six-and-a-half feet of human DNA into a nucleus that averages just five microns in diameter.

Work with fungus uncovering keys to DNA methylation

December 15, 2008

Researchers in a University of Oregon lab have shed more light on the mechanism that regulates DNA methylation, a fundamental biological process in which a methyl group is attached to DNA, the genetic material in cells of ...

Histone modifications control accessibility of DNA

July 14, 2010

( -- n an advanced online publication in Nature Structural & Molecular Biology scientist from Dirk Schübeler's group from the Friedrich Miescher Institute for Biomedical Research provide a genome-wide view of ...

Scientists discover secret life of chromatin

September 1, 2011

Chromatin - the intertwined histone proteins and DNA that make up chromosomes – constantly receives messages that pour in from a cell’s intricate signaling networks: Turn that gene on. Stifle that one.

Recommended for you

Moonlighting molecules: Finding new uses for old enzymes

November 27, 2015

A collaboration between the University of Cambridge and MedImmune, the global biologics research and development arm of AstraZeneca, has led researchers to identify a potentially significant new application for a well-known ...

A new form of real gold, almost as light as air

November 25, 2015

Researchers at ETH Zurich have created a new type of foam made of real gold. It is the lightest form ever produced of the precious metal: a thousand times lighter than its conventional form and yet it is nearly impossible ...

Getting under the skin of a medieval mystery

November 23, 2015

A simple PVC eraser has helped an international team of scientists led by bioarchaeologists at the University of York to resolve the mystery surrounding the tissue-thin parchment used by medieval scribes to produce the first ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.