HOME >> BIOLOGY >> NEWS
How DNA copying enzyme 'stops the presses' for repair synthesizing enzyme

DURHAM, N.C. -- Biochemists have performed detailed structural studies that reveal for the first time how an enzyme key to DNA replication stalls when an error occurs, to allow it to be corrected. Without such instantaneous braking, such mistakes in DNA replication would wreak havoc on DNA replication, killing the cell.

To their surprise, the scientists observed how the enzyme, DNA polymerase, retains a "short-term memory" of mismatches, in some cases halting itself past the point of the mismatch, so that the repair machinery can go to work. They also found that the mismatch structures differed dramatically from those deduced from previous indirect biochemical studies.

In an article in the March 19, 2004, issue of the journal Cell, Duke University Medical Center biochemists Sean Johnson and Lorena Beese, Ph.D., described how they had conducted detailed structural analyses of DNA polymerase as it encountered each of the 12 possible kinds of mismatches possible in DNA replication.

In such replication, the polymerase sequentially attaches DNA units called bases along a single-stranded template DNA. The result is like constructing one rail of a spiral staircase, using the other rail as a guide; and the polymerase "translocates" the template strand through its active site like a thread through the eye of a needle.

In this replication process, the polymerase normally guides the template strand and assembles the complementary, growing "primer" strand by pairing each base with the correct counterpart -- always pairing adenine with thymine and cytosine with guanine.

When mismatches occur, the polymerase must instantly halt itself, triggering the mismatch repair machinery to launch into action, before replication can continue. This stalling is thought to occur because the polymerase-DNA structure is distorted by the mismatched bases, causing it to shut down.

The problem, said Beese, who is an associate professor of biochemistr
'"/>

Contact: Dennis Meredith
dennis.meredith@duke.edu
919-681-8054
Duke University Medical Center
30-Mar-2004


Page: 1 2 3

Related biology news :

1. Two separate controls regulate chromosome copying in yeast
2. Scientists decipher "fail-safe" system that limits gene copying in cells
3. Anthrax enzyme images reveal secrets of antibiotic resistance, suggest new drug design
4. First glimpse of DNA binding to viral enzyme
5. Two enzymes key to calorie-burning, Brown research shows
6. Argonne scientists determine structure of staph, anthrax enzyme
7. Brain serotonin enzyme finding might explain psychiatric disorders
8. Study finds plant enzyme function changes with location in cell
9. Basic RNA enzyme research promises single-molecule biosensors
10. Molecule that blocks key bacterial enzyme may lead to new antibiotics
11. Study finds first evidence COX-2 enzymes can regulate DNA damage

Post Your Comments:
(Date:2/5/2015)... Epic Sciences , a precision diagnostics company dedicated to improving ... , Ph.D., president and CEO, is scheduled to present at ... Valley, which is taking place at the Computer History Museum ... 26-28, 2015. Dr. Prahalad will give a ... Epic Sciences was a finalist in the PMWC,s Most Promising ...
(Date:2/5/2015)... -- New Market Research Reports Title Global ... 2020 has Been Added to GrandViewReseach.com Report Database ... reach USD 5.10 billion by 2020, according to a ... help identify the site of tissue damage in case ... in medical imaging applications. They have been extensively used ...
(Date:2/5/2015)... JOLLA, Calif. , Jan. 30, 2015  It ... the great power and potential for genomic science as ... aid in disease prevention and treatment.  I was honored ... potential new, government-funded precision medicine program. ... advancing the science of genomics—from the first sequenced genome ...
Breaking Biology News(10 mins):Epic Sciences to Present at Personalized Medicine World Conference 2015 on the Use of Circulating Tumor Cells as Cancer Biomarkers 2IR Camera Market Worth $5.10 Billion By 2020: Grand View Research, Inc. 2IR Camera Market Worth $5.10 Billion By 2020: Grand View Research, Inc. 3J. Craig Venter, Ph.D., Co-Founder and CEO, Human Longevity, Inc. (HLI) Participates in White House Precision Medicine Event 2
(Date:2/26/2015)... 2015 On behalf of biotech client ... Wilentz, Goldman & Spitzer, P.A. (Wilentz) secured ... against Genewiz Inc. in excess of $10 million. The ... trade secrets, and that it improperly hired one or ... order denying motions for judgment notwithstanding the verdict, a ...
(Date:2/26/2015)... Calif. , Feb. 26, 2015 The healthcare ... this ever-changing arena, Frost & Sullivan will host its ... Sullivan Executive MindXchange , March 8 to 10, at the ... Diego, Calif. This event is a ... healthcare leaders to discuss industry disruptions and how to succeed ...
(Date:2/26/2015)... The Pittcon 2015 Exposition, which takes ... Morial Convention Center in New Orleans, Louisiana, will ... 2015) displaying products and services used by the ... The Exposition will offer the latest innovations in ... chemistry; drug discovery; nanotechnology; life sciences to include ...
(Date:2/26/2015)... February 26, 2015 Innovation is ... emerging from unexpected parts of the world and ... From agriculture to manufacturing to health care, disruption ... environmental realities and socio-political trends shake the foundations ... key ingredient for CEOs to survive the next ...
Breaking Biology Technology:Wilentz Client GenScript Awarded $10 Million in Trade Secrets Case Against Genewiz 2Wilentz Client GenScript Awarded $10 Million in Trade Secrets Case Against Genewiz 3Embrace the Future of Medical Technologies with Frost & Sullivan 2Embrace the Future of Medical Technologies with Frost & Sullivan 3Pittcon 2015 Announces Exposition Highlights 2One Million Acts of Innovation Canada Creates Partnership with The Economist Events’ Innovation Forum 2
Cached News: