Navigation Links
Stretching the truth: JILA biophysicists help unravel DNA stretching mystery
Date:1/20/2011

Using a new experimental test structure, biophysicists at JILA have unraveled part of a 15-year mystery in the mechanics of DNAjust how the molecule manages to suddenly extend to almost twice its normal length. The new test structure should support research on DNA elasticity as a standard for tiny forces and help refine studies of how drugs and other substances bind to DNA.

In a new paper in the Journal of the American Chemical Society,* JILA scientists disprove a leading explanation for DNA overstretching, a curious behavior in which the molecule's double helix structure (see image) suddenly extends by 70 percent when subjected to 65 picoNewtons (pN) of force. The exact steps of the process have been controversial since overstretching was discovered in 1996. Contrary to a popular theory, the new JILA work shows that DNA's backbone does not need to have a small gap, often called a nick, or sport loose ends for the dramatic extension to occur at 65 pN.

JILA is a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder.

"Overstretching is a really amazing phenomenon, and even after 15 years, people are still debating it," says senior author Tom Perkins, a NIST expert in the mechanics of single molecules. "DNA stretches and stretches like a rubber band and you think it's going to break, and then all of a sudden it nearly doubles in length. Something wonderfully interesting happens at this transition."

The leading theory is that overstretching introduces so much energy that the DNA melts, with a single strand peeling off from nicks in the backbone or free ends. This model assumes that nicks or ends are essential. Scientists did not test this assumption until now because there was no platform for restraining the ends without also locking the molecule's structure and rotation.

The JILA team's key advance was a clever geometry that binds a looped end of DN
'/>"/>

Contact: Laura Ost
laura.ost@nist.gov
303-497-4880
National Institute of Standards and Technology (NIST)
Source:Eurekalert

Page: 1 2

Related biology news :

1. Stretching molecules yields new understanding of electricity
2. Penn biophysicists create new model for protein-cholesterol interactions in brain and muscle tissue
3. Brain structure provides key to unraveling function of bizarre dinosaur crests
4. Gene against bacterial attack unravelled
5. Yale researchers unravel mystery of brain aneurysms
6. Soybean grant gives researchers tools to unravel better bean
7. Chemist receives NIH funding to unravel tricks of neuronal wiring
8. HWI scientist first in world to unravel structure of key breast cancer target enzyme
9. Physics, math provide clues to unraveling cancer
10. Freaks help scientist unravel nature and nurture
11. Study unravels why certain fishes went extinct 65 million years ago
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/23/2014)... conclusive evidence that the source of a unique rhythmic ... called the "bio-duck," is the Antarctic minke whale ( ... personnel in the 1960s who thought it sounded like ... various locations in the Southern Ocean, but its source ... 2013, an international team of researchers deployed acoustic tags ...
(Date:4/23/2014)... the likelihood of an accurate group decision increases with ... when a collective faces a variety of factors ... University researchers report that smaller groups actually tend to ... excessively focused on only certain pieces of information. , ... known about collective intelligence, or the "wisdom of crowds," ...
(Date:4/23/2014)... The shale gas boom has transformed the energy ... locations, it could cause conflict among the energy ... resources, say researchers. They add that degraded water ... adequate safeguards. The feature article appears in the ... , Meagan S. Mauter and colleagues point out ...
Breaking Biology News(10 mins):Scientists identify source of mysterious sound in the Southern Ocean 2Scientists identify source of mysterious sound in the Southern Ocean 3Too many chefs: Smaller groups exhibit more accurate decision-making 2Too many chefs: Smaller groups exhibit more accurate decision-making 3How to avoid water wars between 'fracking' industry and residents 2
... January 11, 2010 Why do some people like to ... hand, taking the opposite tack by buying insurance to reduce ... Hebrew University of Jerusalem and two Asian universities say the ... team set out to tackle the long-standing question in economic ...
... standards to help ensure the quality and enhance the ... and a variety of functional foods are being proposed ... internationally recognized compendium of quality standards for food ingredients. ... breast milk and commonly added to infant formula, and ...
... Ohio Blocking the function of an enzyme in the ... nerve cells from dying after a stroke, new research suggests. ... that the tocotrienol form of vitamin E, an alternative to ... acids that eventually kill neurons. The Ohio State University ...
Cached Biology News:Why do people 'play the longshot' and buy insurance? It's in our genes 2Quality and safety of infant formulas, functional foods enhanced by new standards 2Quality and safety of infant formulas, functional foods enhanced by new standards 3Study reveals how one form of natural vitamin E protects brain after stroke 2Study reveals how one form of natural vitamin E protects brain after stroke 3
(Date:1/15/2014)... Biotechnology Company, Limited ("TaiGen") today announced that they have ... pharmaceutical company, to develop and commercialize nemonoxacin (Taigexyn ® ... Turkey and other members of ... for the treatment of bacterial infections including those caused ...
(Date:1/14/2014)... Carahsoft and CDS Federal Services have ... at 2pm EST (11am PST), “Natural Language Processing: Converting ... how technology can turn raw, heterogeneous data into actionable ... The online webinar will last approximately one hour. , ...
(Date:1/14/2014)... Jan. 14, 2014  3D Communications, a leading provider of strategic communications ... and media events in the United States ... Virginia Cox , JD, is returning to the firm,s ... re-joins 3D after more than two years of service as ...
(Date:1/14/2014)... NY (PRWEB) January 14, 2014 EquitiesIQ, ... Alliqua, Inc. (OTCQB: ALQA). Alliqua is an emerging biomedical ... serve the wound care market. , Free report download: ... restructured with a seasoned management team and Board, which ...
Breaking Biology Technology:TaiGen Biotechnology Signed Exclusive License Agreement with R-Pharm for Nemonoxacin (Taigexyn(R)) 2TaiGen Biotechnology Signed Exclusive License Agreement with R-Pharm for Nemonoxacin (Taigexyn(R)) 3TaiGen Biotechnology Signed Exclusive License Agreement with R-Pharm for Nemonoxacin (Taigexyn(R)) 4Webcast - Natural Language Processing: Converting Raw Data into Actionable Knowledge – Hosted by Carahsoft and CDS Federal Services 2Former FDA Associate Commissioner Returns To 3D Communications 2EquitiesIQ Initiates Coverage of Alliqua, Inc. 2EquitiesIQ Initiates Coverage of Alliqua, Inc. 3
... REDWOOD CITY, Calif., March 4 Maxygen, Inc.,(Nasdaq: ... the development of,improved protein drugs, today announced changes ... president in charge of global,business development and U.S. ... business officer. In addition, the company announced the,pending ...
... new independent non-executive directors added to Board with ... ... appointed independent non-executive Chairman, BRISBANE, Australia, March 4 ... John Lee and Robert Williamson to the Company,s Board as,independent ...
... Biosciences,(Nasdaq: MATK ) announced today that life,sDHA, its ... heart health, is available in new So,Good Omega DHA ... selling soymilk brand. Available in original or vanilla flavor, ... major retailers throughout,Canada., "So Good Omega DHA Soymilk ...
Cached Biology Technology:Maxygen Announces Management Changes 2Progen Expands Board of Directors 2Progen Expands Board of Directors 3Progen Expands Board of Directors 4Canada's Best-Selling Soymilk Now Available with Martek's life'sDHA 2Canada's Best-Selling Soymilk Now Available with Martek's life'sDHA 3
... ProFound Label Transfer Sulfo SBED Protein:Protein ... known as Label Transfer has rapidly gained ... protein interaction discovery. A growing number of ... Biotin Label Transfer Reagent to study a ...
... compact benchtop and stackable multi-function incubator. ... a large display screen to accurately ... circulation inside to evenly distribute temperature ... easily calibrated from the microprocessor controller. ...
... emerging as a powerful new tool for ... only amino groups have been able to ... as our Sulfo-SBED. Sulfhydryl-reactive Mts-Atf-Biotin and its ... to the protein interaction tool chest that ...
... designed as a high tech shaker for ... compensation allows high shaking speed even under ... therefore, faster growth and higher cell density. ... high reproducibility is critical Variable ...
Biology Products: