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Double helix

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In geometry a double helix (plural helices) typically consists of two congruent helices with the same axis, differing by a translation along the axis, which may or may not be half-way.

The term "double helix" is commonly encountered in molecular biology, where it refers to the structure of DNA. The double-helix model of DNA structure was first published in the journal Nature by James D. Watson and Francis Crick in 1953, based upon the crucial X-ray diffraction image of DNA (labeled as "Photo 51") from Rosalind Franklin in 1952 , followed by her more clarified DNA image with Raymond Gosling, Maurice Wilkins, Alexander Stokes and Herbert Wilson, as well as base-pairing chemical and biochemical information by Erwin Chargaff.

Crick, Wilkins and Watson each received one third of the 1962 Nobel Prize in Physiology or Medicine for their contributions to the discovery. (Franklin, whose breakthrough X-ray diffraction data was used to formulate the DNA structure, died in 1958, and thus was ineligible to be nominated for a Nobel Prize.)

The DNA double helix is a right-handed spiral polymer of nucleic acids, held together by nucleotides which base pair together. A single turn of the helix constitutes ten nucleotides. The double helix structure of DNA contains a major groove and minor groove, the major groove being wider than the minor groove. Given the difference in widths of the major groove and minor groove, many proteins which bind to DNA do so through the wider major groove .

The order, or sequence, of the nucleotides in the double helix within a gene specifies the primary structure of a protein.

The term entered popular culture with the publication in 1968 of The Double Helix: A Personal Account of the Discovery of the Structure of DNA, by James Watson.

For more information about Double helix, read the full article at Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.


News tagged with double helix

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Understanding DNA Repair and Cancer

Biology / Cell & Microbiology

created Dec 03, 2009 | popularity not rated yet | comments 0

(PhysOrg.com) -- A protein that plays a key role in copying DNA also plays a vital role in repairing breaks in it, UC Davis scientists have found. The work is helping researchers understand how cancer cells can resist radiation ...


Two proteins act as molecular tailors in DNA repair

Medicine & Health / Research

created Nov 13, 2009 | popularity not rated yet | comments 0

(PhysOrg.com) -- On average, our cells encounter a very lethal form of DNA damage 10 times a day. Lucky for us, we have the capacity to repair each and every one of them. New research now reveals exactly how two well-known ...


The x-ray machine has revolutionised how doctors detect disease and injury

X-ray named top achievement by British museum

Other Sciences / Other

created Nov 04, 2009 | popularity 4 / 5 (1) | comments 0

The X-ray was named the most important modern scientific achievement Wednesday in a poll conducted for Britain's Science Museum, beating Apollo spacecraft and DNA.


Single-stranded DNA-binding protein is dynamic, critical to DNA repair

Single-stranded DNA-binding protein is dynamic, critical to DNA repair

Chemistry / Biochemistry

created Oct 21, 2009 | popularity 5 / 5 (1) | comments 0

Researchers report that a single-stranded DNA-binding protein (SSB), once thought to be a static player among the many molecules that interact with DNA, actually moves back and forth along single-stranded ...


Scientists decipher the 3-D structure of the human genome

Scientists decipher the 3-D structure of the human genome

Medicine & Health / Genetics

created Oct 08, 2009 | popularity 5 / 5 (16) | comments 1

(PhysOrg.com) -- Scientists have deciphered the three-dimensional structure of the human genome, paving the way for new insights into genomic function and expanding our understanding of how cellular DNA folds ...


Models begin to unravel how single DNA strands combine

Nanotechnology / Bio & Medicine

created Oct 05, 2009 | popularity 5 / 5 (1) | comments 0

(PhysOrg.com) -- Using computer simulations, a team of University of Wisconsin-Madison researchers has identified some of the pathways through which single complementary strands of DNA interact and combine to form the double ...


Chemists Reach from the Molecular to the Real World with Creation of 3-D DNA Crystals

Chemists Reach from the Molecular to the Real World with Creation of 3-D DNA Crystals

Chemistry / Materials Science

created Sep 02, 2009 | popularity 4.7 / 5 (6) | comments 0

(PhysOrg.com) -- New York University chemists have created three-dimensional DNA structures, a breakthrough bridging the molecular world to the world where we live. The work, reported in the latest issue of ...


Gene transcribing machine takes halting, backsliding trip along the DNA

Gene transcribing machine takes halting, backsliding trip along the DNA

Chemistry / Biochemistry

created Jul 30, 2009 | popularity 5 / 5 (4) | comments 1

(PhysOrg.com) -- The body's nanomachines that read our genes don't run as smoothly as previously thought, according to a new study by University of California, Berkeley, scientists.


Professor sheds light on DNA mechanisms

Chemistry / Biochemistry

created Jul 17, 2009 | popularity 4.5 / 5 (2) | comments 0

By manipulating individual atoms in DNA and forming unique molecules, a Georgia State University researcher hopes to open new avenues in research towards better understanding the mechanisms of DNA replication and transcription, ...


New information about DNA repair mechanism could lead to better cancer drugs

Biology / Cell & Microbiology

created Jul 16, 2009 | popularity not rated yet | comments 0

Researchers at Washington University School of Medicine in St. Louis have shed new light on a process that fixes breaks in the genetic material of the body's cells. Their findings could lead to ways of enhancing chemotherapy ...


Researchers unravel mystery of DNA conformation

Biology / Cell & Microbiology

created Jul 13, 2009 | popularity 5 / 5 (1) | comments 1

An iconic photograph (http://img.timeinc.net/time/80days/images/530228.jpg) of Nobel laureates Drs. Francis Crick and James Watson show the pair discussing with a rigid model of the famous double helix. ...


Backtracking on DNA

Backtracking on DNA

Physics / General Physics

created Jun 23, 2009 | popularity 4.6 / 5 (9) | comments 0

(PhysOrg.com) -- Accuracy is essential for life, so in converting the information stored in DNA into a form in which it can be used, a high level of precision is required. Dr Tanniemola Liverpool from the ...


Scientists find shared genetic link between periodontitis and heart attack

Medicine & Health / Genetics

created May 25, 2009 | popularity 4.5 / 5 (2) | comments 0

The relationship between the dental disease periodontitis and coronary heart disease (CHD) has been known for several years. Although a genetic link seemed likely, until now its existence was uncertain. Now, for the first ...


nature journal

Chemists see first building blocks to life on Earth

Chemistry / Biochemistry

created May 13, 2009 | popularity 4.9 / 5 (25) | comments 13

Scientists at The University of Manchester have developed an experiment that sheds new and fascinating light on how life on Earth might have begun.


New nucleotide could revolutionize epigenetics

Biology / Cell & Microbiology

created Apr 16, 2009 | popularity 4.8 / 5 (6) | comments 0

Anyone who studied a little genetics in high school has heard of adenine, thymine, guanine and cytosine - the A,T,G and C that make up the DNA code. But those are not the whole story. The rise of epigenetics in the past decade ...