Navigation Links
Major advance made on DNA structure

Oregon State University researchers have made significant new advances in determining the structure of all possible DNA sequences ?a discovery that in one sense takes up where Watson and Crick left off, after outlining in 1953 the double-helical structure of this biological blueprint for life.

One of the fundamental problems in biochemistry is to predict the structure of a molecule from its sequence ?this has been referred to as the "Holy Grail" of protein chemistry.

Today, the OSU scientists announced in the Proceedings of the National Academy of Sciences that they have used X-ray crystallography to determine the three-dimensional structures of nearly all the possible sequences of a macromolecule, and thereby create a map of DNA structure.

As work of this type expands, it should be fundamentally important in explaining the actual biological function of genes - in particular, such issues as genetic "expression," DNA mutation and repair, and why some DNA structures are inherently prone to damage and mutation. Understanding DNA structure, the scientists say, is just as necessary as knowing gene sequence. The human genome project, with its detailed explanation of the genetic sequence of the entire human genome, is one side of the coin. The other side is understanding how the three-dimensional structure of different types of DNA are defined by those sequences, and, ultimately, how that defines biological function.

"There can be 400 million nucleotides in a human chromosome, but only about 10 percent of them actually code for genes," said Pui Shing Ho, professor and chair of the OSU Department of Biochemistry and Biophysics. "The other 90 percent of the nucleotides may play different roles, such as regulating gene expression, and they often do that through variations in DNA structure."

"Now, for the first time, we're really starting to see what the genome looks like in three dimensional reality, not just what the sequence of genes i s," Ho said. "DNA is much more than just a string of letters, it's an actual structure that we have to explore if we ever hope to understand biological function. This is a significant step forward, a milestone in DNA structural biology."

In the early 1950s, two researchers at Cambridge University ?James Watson and Francis Crick ?made pioneering discoveries by proposing the double-helix structure of DNA, along with another research group in England about the same time. They later received the Nobel Prize for this breakthrough, which has been called the most important biological work of the past century and revolutionized the study of biochemistry. Some of the other early and profoundly important work in protein chemistry was done by Linus Pauling, an OSU alumnus and himself the recipient of two Nobel Prizes.

However, Watson and Crick actually identified only one structure of DNA, called B-DNA, when in fact there are many others ?one of which was discovered and another whose structure was solved at OSU in recent years ?that all have different effects on genetic function.

Aside from the genetic sequence that DNA encodes, the structure of the DNA itself can have profound biological effects, scientists now understand. Until now, there has been no reliable method to identify DNA structure from sequence, and learn more about its effects on biological function.

In their studies, the OSU scientists used X-ray examination of crystalline DNA to reconstruct exactly what the DNA looks like at the atomic level. By determining 63 of the 64 possible DNA sequences, they were able to ultimately determine the physical structure of the underlying DNA for all different types of sequences. Another important part of this study is the finding that the process of DNA crystallization does not distort its structure.

"Essentially, this is a proof of concept, a demonstration that this approach to studying DNA structure will work, and can ultimately be use d to help understand biology," Ho said.

For instance, one of the unusual DNA structures called a Holliday junction, whose structure was co-solved at OSU about five years ago, apparently plays a key role in DNA's ability to repair itself ?a vital biological function.

A more fundamental understanding of DNA structure and its relationship to genetic sequences, researchers say, helps set the stage for applied advances in biology, biomedicine, genetic engineering, nanotechnology and other fields.

The recent work was supported by grants from the National Institutes of Health and the National Science Foundation.


Source:Oregon State University

Related biology news :

1. Major new UNC-based drinking water study suggests pregnancy fears may be overstated
2. Major breakthrough in the treatment of cancers and infectious diseases
3. Major WHO study concludes calcium supplements can reduce complications during pregnancy
4. Major obesity gene is lost in the shuffle
5. Major initiative proposed to address amphibian crisis
6. Major cancer study aims to identify protein markers for early-stage disease
7. Major link in brain-obesity puzzle found
8. Major gene study uncovers secrets of leukemia
9. Research advances quest for HIV-1 vaccine
10. Inexpensive, mass-produced genes core of synthetic biology advances at UH
11. Study of genomic DNA leads to new advances in cancer diagnostics
Post Your Comments:

(Date:5/12/2016)... 12, 2016 , a brand ... overview results from the Q1 wave of its quarterly ... was consumers, receptivity to a program where they would ... health insurance company. "We were surprised to ... Michael LaColla , CEO of Troubadour Research, "primarily ...
(Date:4/28/2016)... India , April 28, 2016 ... Infosys (NYSE: INFY ), and Samsung SDS, a ... that will provide end customers with a more secure, ... services.      (Logo: ) , ... services, but it also plays a fundamental part in enabling ...
(Date:4/26/2016)... Research and Markets has announced ... 2016-2020"  report to their offering.  , ,     (Logo: ... analysts forecast the global multimodal biometrics market to ... period 2016-2020.  Multimodal biometrics is being ... the healthcare, BFSI, transportation, automotive, and government for ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... /PRNewswire/ - FACIT has announced the creation of ... company, Propellon Therapeutics Inc. ("Propellon" or "the Company"), ... portfolio of first-in-class WDR5 inhibitors for the treatment ... represent an exciting class of therapies, possessing the ... cancer patients. Substantial advances have been achieved with ...
(Date:6/23/2016)... 2016  The Biodesign Challenge (BDC), a university competition ... harness living systems and biotechnology, announced its winning teams ... New York City . The ... projects at MoMA,s Celeste Bartos Theater during the daylong ... senior curator of architecture and design, and Suzanne ...
(Date:6/23/2016)... Ky. , June 23, 2016 ... two Phase 1 clinical trials of its complement ... placebo-controlled, single and multiple ascending dose studies designed ... pharmacodynamics (PD) of subcutaneous injection in healthy adult ... subcutaneously (SC) either as a single dose (ranging ...
(Date:6/23/2016)... ... June 23, 2016 , ... Regulatory Compliance Associates® Inc. (RCA), ... free webinar on Performing Quality Investigations: Getting to Root Cause. ... no charge. , Incomplete investigations are still a major concern to the Regulatory ...
Breaking Biology Technology: