Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


DNA Caught Rock 'N Rollin'

DNA, that marvelous, twisty molecule of life, has an alter ego, research at the University of Michigan and the University of California, Irvine reveals.

On rare occasions, its building blocks "rock and roll," deforming the familiar double helix into a different shape.

"We show that the simple DNA double helix exists in an alternative form---for one percent of the time---and that this alternative form is functional," said Hashim M. Al-Hashimi, who is the Robert L. Kuczkowski Professor of Chemistry and Professor of Biophysics at U-M. "Together, these data suggest that there are multiple layers of information stored in the genetic code." The findings were published online Jan. 26 in the journal Nature.

It's been known for some time that the DNA molecule can bend and flex, something like a rope ladder, but throughout these gyrations its building blocks---called bases---remain paired up just the way they were originally described by James Watson and Francis Crick, who proposed the spiral-staircase structure in 1953. By adapting nuclear magnetic resonance (NMR) technology, Al-Hashimi's group was able to observe transient, alternative forms in which some steps on the stairway come apart and reassemble into stable structures other than the typical Watson-Crick base pairs.

The question was, what were these alternative stable structures?

"Using NMR, we were able to access the chemical shifts of this alternative form," said graduate student Evgenia Nikolova. "These chemical shifts are like fingerprints that tell us something about the structure." Through careful analysis, Nikolova realized the "fingerprints" were typical of an orientation in which certain bases are flipped 180 degrees.

"It's like taking half of the stairway step and flipping it upside down so that the other face now points up," said Al-Hashimi. "If you do this, you can still put the two halves of the step back together, but now what you have is no longer a Watson-Crick base pair; it's something called a Hoogsteen base pair."

"Using computational modeling, we further validated that individual bases can roll over inside the double helix to achieve these Hoogsteen base pairs," said Ioan Andricioaei, an associate professor of chemistry at the University of California, Irvine.

Hoogsteen base pairs have previously been observed in double-stranded DNA, but only when the molecule is bound to proteins or drugs or when the DNA is damaged. The new study shows that even under normal circumstances, with no outside influence, certain sections of DNA tend to briefly morph into the alternative structure, called an "excited state."

Previous studies of DNA structure have relied mainly on techniques such as X-ray and conventional NMR, which can't detect such fleeting or rare structural changes.

"These methods do not capture alternative DNA structural forms that may exist for only a millisecond or in very little abundance, such as one percent of the time," said Al-Hashimi. "We took new solution NMR methods that previously have been used to study rare deformations in proteins and adapted them so that they could be used to study rare states in nucleic acids. Now that we have the right tools to look at these so-called excited states, we may find other short-lived states in DNA and RNA."

Because critical interactions between DNA and proteins are thought to be directed by both the sequence of bases and the flexing of the molecule, these excited states represent a whole new level of information contained in the genetic code, Al-Hashimi said.

In addition to Al-Hashimi, Nikolova and Andricioaei, the paper's authors are undergraduate student Abigail Wise and assistant professor of biological chemistry Patrick O'Brien of U-M and postdoctoral researcher Eunae Kim of the University of California, Irvine.

The researchers received funding from the National Science Foundation, the National Institutes of Health and the University of Michigan.

More information:

Hashim Al-Hashimi:


Nancy Ross-Flanigan | Newswise Science News
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>