Navigation Links
Surprise finding for stretched DNA

Most of us are familiar with the winding staircase image of DNA, the repository of a biological cell's genetic information. But few of us realize just how tightly that famous double helix is wound. Stretched to its full length, a single molecule of human DNA extends more than three feet, but, when wound up inside the nucleus of a cell, that same molecule measures about one millionth of an inch across. Biologists have long believed that as a molecule of DNA is stretched, its double helix starts to unwind. As much sense as this makes from an intuitive standpoint, a recent experiment proved it not to be the case.

Researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California at Berkeley used a combination of microscopic beads and magnetic tweezers to observe that when a DNA molecule is stretched, it actually begins to overwind. This overwinding continues until the force being applied to stretch the DNA exceeds about 30 picoNewtons. (One picoNewton is about a trillionth the force required to hold an apple against Earth's gravity.) Beyond the 30 picoNewton threshold, the DNA double helix did begin to unwind in accordance with predictions.

"DNA's helical structure implies that twisting and stretching should be coupled, hence the prediction that DNA should unwind when stretched," said biophysicist Carlos Bustamante, who led this experiment. "That is why it was such surprise when we directly measured twist-stretch coupling to find instead DNA overwinds when stretched. The DNA molecule, when studied at close range, continues to surprise us!"

Bustamante is a leading authority on the use of single-molecule visualization and manipulation techniques to study the dynamics, structure and kinetics of molecular motors and nucleo-protein assemblies. He holds joint appointments with Berkeley Lab's Physical Biosciences Division and UC Berkeley's Departments of Molecular & Cell Biol
'"/>

Source:DOE/Lawrence Berkeley National Laboratory


Page: 1 2 3

Related biology news :

1. Surprising findings reported about iron overload
2. Liposome finding implies electrical effect on cell development
3. Evolution of life on Earth may hold key to finding life in outer space
4. LIAI scientists make major finding on potential smallpox treatment
5. Study findings offer potential new targets for antibiotics
6. The worlds deepest dinosaur finding - 2256 metres below the seabed
7. Protein finding could lead to treatment for inflammatory diseases
8. Oops! Researchers publish new findings on the brains response to costly mistakes
9. Inside rocks, implications for finding life on Mars
10. Biodiversity key to sustainable biofuel according to University of Minn. researchers findings
11. New findings offer more complete view of breast cancer gene mutations in US population
Post Your Comments:
*Name:
*Comment:
*Email:
TAG: Surprise finding for stretched DNA

(Date:8/27/2014)... described by the Volunteer Wildfire Services of South Africa ... government warned residents in certain parts of the province ... A high veld fire danger rating is expected ... the Great Kei and Mnquma area. Strong winds ... The thunderstorms bring lightning strikes and subsequent fire and ...
(Date:8/27/2014)... . , Charcot-Marie-Tooth ... affecting the peripheral nervous system. Researchers from the Department ... Medicine and University Medical Centre Gttingen have discovered that ... with the disease. These cells enwrap the nerve fibres ... the rapid transfer of electrical impulses. If Schwann cells ...
(Date:8/27/2014)... New evidence puts into doubt the long-standing belief that ... the brain plays a central role in depression. ... report that mice lacking the ability to make serotonin ... by conventional wisdom) did not show depression-like symptoms. ... Dingell VA Medical Center and Wayne State University School ...
Breaking Biology News(10 mins):Potential therapy for incurable Charcot-Marie-Tooth disease 2New study throws into question long-held belief about depression 2
... University of New Mexico (UNM), Brown University, and House Ear ... simplex virus type 1 (HSV1) infections growing inside cells. HSV1, ... latent form inside nerve cells. Re-activation and growth of HSV1 ... are published in the March 31 issue of PLoS ...
... United States in late 2004, many producers feared devastating yield ... world. In response to this threat, researchers have been evaluating ... a recent report in Crop Science identifies some ... which of the soybean germplasm accessions were resistant in the ...
... , HELSINKICould "interventions" bring children closer to nature? Researchers ... HortTechnology compares urban and rural children,s relationships ... children. In Finland, a country famous for its ... Department of Agricultural Sciences at the University of Helsinki ...
Cached Biology News:Researchers link herpes to Alzheimer's disease 2Soybean germplasm evaluations give US a head start against soybean rust pathogen 2Soybean germplasm evaluations give US a head start against soybean rust pathogen 3Researchers say children need horticultural interventions 2
(Date:8/27/2014)... 2014 Varian Medical Systems today broke ... Salt Lake City manufacturing facility and allow for the ... ultimately create 1,000 new full time jobs in the ... is home to hardworking people with immense engineering and ... Varian’s success in the manufacturing of our state-of-the-art X-ray ...
(Date:8/27/2014)... 27, 2014 Reportlinker.com announces that ... in its catalogue: Global Biodegradable ... http://www.reportlinker.com/p02316661/Global-Biodegradable-Packaging-Materials-Market-2014-2018.html About Biodegradable ... are readily decomposed by the action of ... packaging in terms of raw materials, production ...
(Date:8/27/2014)... , Aug. 27, 2014 Reportlinker.com ... available in its catalogue: Global Chelating ... About Chelating Agent A chelating ... covalent bonds with metal ions, thereby forming a ... some metal-ions have on chemical processes, formulations, and ...
(Date:8/27/2014)... 27, 2014 “We are honored to ... said Ven Thangaraj, CEO of Radiant Sage. “We are ... taking the imaging corelab market to a different level. ... research organizations to efficiently and effectively manage the massive ... to be analyzed and read by trained physicians. Being ...
Breaking Biology Technology:Varian Medical Systems Groundbreaking on Facility Expansion Triggers Influx of New Jobs to Salt Lake 2Varian Medical Systems Groundbreaking on Facility Expansion Triggers Influx of New Jobs to Salt Lake 3Global Biodegradable Packaging Materials Market 2014-2018 2Global Biodegradable Packaging Materials Market 2014-2018 3Global Biodegradable Packaging Materials Market 2014-2018 4Global Biodegradable Packaging Materials Market 2014-2018 5Global Biodegradable Packaging Materials Market 2014-2018 6Global Biodegradable Packaging Materials Market 2014-2018 7Global Chelating Agents Market 2014-2018 2Global Chelating Agents Market 2014-2018 3Global Chelating Agents Market 2014-2018 4Radiant Sage Named to CIOReview List of 100 Most Promising Technology Companies 2
... ... woman found dead four days after receiving the Gardasil vaccine has filed an ... been asked to bar lawsuits against manufacturers of defectively designed vaccines. The ... have a lessened incentive to produce a safe vaccine and public trust in ...
... ... ... 16, 2010 -- The American Medical Writers Association named medical writer, Rita Buckley, Writer/Owner ... for Excellence in Medical Communication. She received the awards for The Lehman Series Expert ...
... IRVINE, California and KARLSRUHE, Germany , June 16, 2010 ... Germany and the US. "Growth requires space" had already been the motto of,the ... , ... joimax(R) Inc. is moving from Campbell to Irvine, California , one,of ...
Cached Biology Technology:Supreme Court Amicus Brief Filed Opposing Lawsuit Protection for Manufacturers of Defectively Designed Vaccines 2Medical Writer Rita Buckley Wins Awards for Excellence in Medical Communication 2Medical Writer Rita Buckley Wins Awards for Excellence in Medical Communication 3joimax(R) Moves Into Larger Premises 2
RABBIT ANTI HUMAN CHYMOTRYPSIN...
... Captivate magnetic separator for ... used in conjunction with the ... C-21476) or other magnetic particles ... mL microcentrifuge tubes. Cell Biology ...
This issue concentrated on the purification of proteins for specific purposes (i.e. large-scale purification, purification for therapeutic use, etc.)...
... • This book describes the basic ... preparing samples for protein transfer and ... bioluminescence-enhanced detection systems are also included. ... and characterization of glycoprotein carbohydrate chains ...
Biology Products: