Featured Research

from universities, journals, and other organizations

UT Southwestern Researchers Discover Structure Of Molecule That Repairs Sun And Cigarette Damage

Date:
October 14, 1999
Source:
University Of Texas Southwestern Medical Center At Dallas
Summary:
The crystal structure of an enzyme that hunts down DNA damage caused by sunlight and cigarettes then snaps it up like a Venus' flytrap is described in the latest Proceedings of the National Academy of Sciences.

DALLAS -- October 12, 1999 -- The crystal structure of an enzyme that hunts down DNA damage caused by sunlight and cigarettes then snaps it up like a Venus' flytrap is described in today's Proceedings of the National Academy of Sciences.

Related Articles


UT Southwestern Medical Center at Dallas researchers provide the first structural information on any component of the deoxyribonucleic acid (DNA) nucleotide excision repair (NER) system, living organisms' most fundamental and important repair mechanism. Knowledge of how the NER system recognizes and disposes of DNA damage eventually may lead to preventions for various forms of cancer.

"When this system breaks down a variety of diseases can develop, most notably xeroderma pigmentosum, a disease associated with neurological abnormalities and a very high incidence of skin cancer," said Dr. Mischa Machius, who collaborated on the study with Dr. Johann Deisenhofer, Nobel laureate, professor of biochemistry and Howard Hughes Medical Institute (HHMI) investigator. "The enzyme also will recognize and remove DNA damage done by cancer therapies designed to kill tumor cells. In that way, the NER mechanism is counterproductive to radiation and chemotherapy."

Until the UT Southwestern scientists solved the crystal structure of the central component of the NER system - the Ultimate Damage Recognition component UvrB - little was known about the structural basis of how the system differentiates between healthy and damaged DNA and how it recognizes a variety of lesions.

Although the researchers looked at UvrB as part of the bacterial NER system, which operates with only three enzymes, UvrB functions in the same way in the corresponding human DNA repair system. The human mechanism contains 16 components.

"UvrB is a remarkably versatile enzyme," said Machius, lead author of the study and a HHMI postdoctoral fellow. "It binds to any DNA, then, along with another enzyme, travels along patrolling for a damaged spot. Once it finds a lesion, it tightens its grip on that DNA segment."

After UvrB attaches to the DNA, it unwinds the two strands of DNA and separates them. Then the NER system incises the lesion on each side and disposes of it.

The UT Southwestern scientists said their observations of the crystal structure shed light on the workings of UvrB in restoring DNA and preventing disease development.

"We believe that UvrB actually traps the damage site in one of its domains," Machius said, "a mechanism that was entirely unexpected and that is unprecedented in nature."

Previous studies have suggested that NER recognizes damage because of how a lesion affects DNA flexibility rather than because of its chemical makeup.

This model, if proven, would help to explain the whole NER system and could aid in development of more effective cancer drugs.

The other researchers involved in the study were HHMI research technicians Lisa Henry and Maya Palnitkar.


Story Source:

The above story is based on materials provided by University Of Texas Southwestern Medical Center At Dallas. Note: Materials may be edited for content and length.


Cite This Page:

University Of Texas Southwestern Medical Center At Dallas. "UT Southwestern Researchers Discover Structure Of Molecule That Repairs Sun And Cigarette Damage." ScienceDaily. ScienceDaily, 14 October 1999. <www.sciencedaily.com/releases/1999/10/991014075631.htm>.
University Of Texas Southwestern Medical Center At Dallas. (1999, October 14). UT Southwestern Researchers Discover Structure Of Molecule That Repairs Sun And Cigarette Damage. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/1999/10/991014075631.htm
University Of Texas Southwestern Medical Center At Dallas. "UT Southwestern Researchers Discover Structure Of Molecule That Repairs Sun And Cigarette Damage." ScienceDaily. www.sciencedaily.com/releases/1999/10/991014075631.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Doctor in NYC Quarantined With Ebola

Doctor in NYC Quarantined With Ebola

AP (Oct. 24, 2014) An emergency room doctor who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus. He's quarantined in a hospital. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins