Images of enzyme suggest way to improve DNA sequencing

St. Louis, Aug. 16, 1999 -- Like a temperamental copy machine, the most commonly used enzyme in DNA sequencing has a few annoying quirks. It generates pages with blank spots, for example. But new X-ray images of the enzyme at work have suggested a way to fix these problems. The strategy works in the lab and is being tested by several companies in the United States.

"We expect this will make the enzyme an even better sequencing tool for the Human Genome Project," says Gabriel Waksman, Ph.D., an associate professor of biochemistry and molecular biophysics at Washington University School of Medicine in St. Louis, one of the world's major sequencing sites. Waksman and colleagues report their findings about the enzyme, Taq DNA polymerase, in the Aug. 17 issue of Proceedings of the National Academy of Sciences.

The Sanger method is the most common method for determining the order of genetic letters, called nucleotides, in DNA. It uses Taq to copy segments of DNA into chains of different lengths. Because Taq comes from a bacterium, Thermus aquaticus, that flourishes in hot springs, it can withstand the temperature changes necessary for copying.

Four genetic letters -- A, T, C and G -- make up the DNA code, and all of these nucleotides are included in the reaction mixture when Taq is put to work. But because a nucleotide-like compound called a dideoxynucleotide triphosphate -- ddC, ddG, ddA or ddT -- also is included, Taq stops copying when it incorporates that compound, like a train that halts on the track when it hits a rock. Therefore, the length of a new DNA chain indicates where that particular nucleotide occurred. After the copies are separated by size and reacted with fluorescent chemicals, DNA sequencing machines can determine which nucleotide terminates each chain. Because A is complementary to T and C to G, this reveals the order of the nucleotides in the original piece of DNA.

Waksman and colleagues obtained X-ray images of Taq at wor

Contact: Linda Sage
Washington University School of Medicine

Page: 1 2 3

Related biology news :

1. Images of tail of protein needed for cell multiplication suggest anticancer drug targets
2. Images reveal how rotavirus - leading cause of diarrhea - enters cells
3. Images reveal how body regulates salt uptake in cells
4. Images of evolution
5. Laser Microscope At Cornell Images Serotonin In Live Cells
6. Anthrax enzyme images reveal secrets of antibiotic resistance, suggest new drug design
7. First glimpse of DNA binding to viral enzyme
8. Two enzymes key to calorie-burning, Brown research shows
9. Argonne scientists determine structure of staph, anthrax enzyme
10. Brain serotonin enzyme finding might explain psychiatric disorders
11. Study finds plant enzyme function changes with location in cell

Post Your Comments:

(Date:8/12/2020)... ... August 11, 2020 , ... Both ... NJ, have entered into license agreements with Housey Pharma’s HMI subsidiary to gain ... and J&J have annual Research and Development spending in excess of US $10 ...
(Date:8/7/2020)... SAN FRANCISCO (PRWEB) , ... August 06, 2020 ... ... the life sciences industry, is pleased to announce that Eric Chen and Jessica ... Vice President of Product Management & Strategy, respectively. , Eric Chen heads development ...
(Date:8/5/2020)... Fla. (PRWEB) , ... August 05, 2020 , ... Regenative ... cover two new innovations, CoreText™ and ProText™, making them the first Wharton’s jelly allografts ... defect using a syringe. The company’s solutions are the first Wharton’s jelly allograft product ...
Breaking Biology News(10 mins):
(Date:8/12/2020)... ... August 12, 2020 , ... Inc. magazine ... global leader in FDA compliance consulting has been named on its annual Inc. ... list represents a unique look at the most successful companies within the American ...
(Date:8/3/2020)... ... , ... Introducing Ardent Animal Health – MediVet Biologics rebrands company and positions ... as MediVet Biologics since its formation in 2016, the company is relaunching itself under ... build on its base of innovative therapies for osteoarthritis and cancer. , ...
(Date:7/31/2020)... ... July 29, 2020 , ... ... transmitter systems that can be configured to drive Klystrons, TWTs, IOTs, and magnetrons. ... drive one or two switches in a push-pull configuration; yielding fast fall time ...
(Date:7/31/2020)... ... , ... eSource has long been touted as the solution to high data ... the reasons it did not take off as quickly as people initially expected, and ... moving towards capturing data electronically for clinical trials and then repurposing it for downstream ...
Breaking Biology Technology:
Cached News: