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:8/4/2015)... -- AMRI (NASDAQ: AMRI ) today reported financial and operating results ... , Second quarter contract revenue of $ 85.2 ... Adjusted contract margins of 26 % , ... decrease in EPS from royalties in the current quarter ... "We are very pleased to present another strong financial quarter, with ...
(Date:7/31/2015)... -- Den 10. internationale konference om Genomik (ICG-10, ... 25. oktober i Shenzhen , Kina. ... år. Siden starten i 2006 er ICB blevet en ... er en af de mest dynamiske, entusiastiske og sjove ... gennembrud og fremskridt inden for ,omik,-forskning, som yderligere vil ...
(Date:7/31/2015)... de julho de 2015 A 10 a. ... será realizada pela BGI de 22-25 de outubro de 2015, ... A conferência está celebrando seu 10 o. aniversário ... se tornou uma das reuniões mais influentes do mundo ... mais dinâmicos, entusiastas e prazerosos. A ...
Breaking Biology News(10 mins):AMRI Announces Second Quarter 2015 Results 2AMRI Announces Second Quarter 2015 Results 3AMRI Announces Second Quarter 2015 Results 4AMRI Announces Second Quarter 2015 Results 5AMRI Announces Second Quarter 2015 Results 6AMRI Announces Second Quarter 2015 Results 7AMRI Announces Second Quarter 2015 Results 8AMRI Announces Second Quarter 2015 Results 9AMRI Announces Second Quarter 2015 Results 10AMRI Announces Second Quarter 2015 Results 11AMRI Announces Second Quarter 2015 Results 12AMRI Announces Second Quarter 2015 Results 13AMRI Announces Second Quarter 2015 Results 14AMRI Announces Second Quarter 2015 Results 15AMRI Announces Second Quarter 2015 Results 16AMRI Announces Second Quarter 2015 Results 17AMRI Announces Second Quarter 2015 Results 18AMRI Announces Second Quarter 2015 Results 19AMRI Announces Second Quarter 2015 Results 20AMRI Announces Second Quarter 2015 Results 21AMRI Announces Second Quarter 2015 Results 22AMRI Announces Second Quarter 2015 Results 23AMRI Announces Second Quarter 2015 Results 24Den 10. internationale konference om Genomics (ICG-10) åbner i oktober 2A 10a. Conferência Internacional sobre Genômica (ICG-10) será em outubro 2A 10a. Conferência Internacional sobre Genômica (ICG-10) será em outubro 3
(Date:8/3/2015)... Delaware , August 3, 2015 ... in the commercialization of its Bio-electrical Signal Therapy device ... noninvasive treatment of hard to heal chronic wounds, today ... agreement with Chemipal, an Israeli distributor specializing in medical ... device. Chemipal is a 70 years old, ...
(Date:7/31/2015)... July 31, 2015 In today,s fast ... help them drive positive health outcomes, improve profitability ... of patient care in their communities. At ThoughtSpot ... and conference, AmerisourceBergen announced a new set of ... Administration Organization and help independent pharmacies endure the ...
(Date:7/30/2015)... 2015 AACC welcomed thousands of medical ... Annual Meeting & Clinical Lab Expo in ... meeting showcased revolutionary advancements in clinical testing technology ... providers to diagnose patients quickly and accurately and ... As of Wednesday, July 29, more ...
(Date:7/30/2015)... San Diego , CA (PRWEB) , ... July ... ... Biopharma, announced the successful completion of a field clinical study of its canine ... being developed together with Aratana Therapeutics (Kansas City, KS) and will be marketed ...
Breaking Biology Technology:E-QURE Corp Signs Second Distribution Agreement in Israel 2E-QURE Corp Signs Second Distribution Agreement in Israel 3AmerisourceBergen Unveils Suite of Enhanced Capabilities for Independent Pharmacies at ThoughtSpot 2015 2AmerisourceBergen Unveils Suite of Enhanced Capabilities for Independent Pharmacies at ThoughtSpot 2015 3Innovative Research on Cancer, Heart Disease, and Infectious Diseases Draws More than 17,500 Attendees to 2015 AACC Annual Meeting 2Innovative Research on Cancer, Heart Disease, and Infectious Diseases Draws More than 17,500 Attendees to 2015 AACC Annual Meeting 3Innovative Research on Cancer, Heart Disease, and Infectious Diseases Draws More than 17,500 Attendees to 2015 AACC Annual Meeting 4VetStem Biopharma Successfully Completes Large Milestone Efficacy Study for its Flagship Canine Osteoarthritis Stem Cell Product 2VetStem Biopharma Successfully Completes Large Milestone Efficacy Study for its Flagship Canine Osteoarthritis Stem Cell Product 3
Cached News: