Navigation Links
Recombination protein dynamics observed with single monomer resolution

Using a sensitive, single-molecule measurement technique, researchers at the University of Illinois at Urbana-Champaign have observed the life cycle of RecA, a protein that plays a major role in repairing damaged DNA.

The protein forms a filament, which grows and shrinks primarily by one monomer at a time, the researchers report in the August issue of the journal Cell.

RecA is a DNA recombination protein found in the gut bacterium E. coli. A human homolog, called Rad51, interacts with many proteins, including BRCA2, whose mutation increases susceptibility to breast and ovarian cancers. A better understanding of how these proteins function could help our understanding of cancer.

"Our measurement technique provides a way of counting the number of individual monomers bound to DNA in real time," said Taekjip Ha, a professor of physics at Illinois and a Howard Hughes Medical Institute investigator. "With that, we can determine the kinetic rates for reactions occurring at either end of the protein filament."

During the recombination process, RecA binds with DNA to form a filament that spirals around the DNA. The filament can grow in either direction, and can advance on the DNA by growing at the leading end and dissociating at the trailing end.

To study the dynamics of RecA, the researchers used a highly sensitive single-molecule fluorescence resonance energy transfer (FRET) technique that Ha and colleagues developed.

To use FRET, researchers first attach two dye molecules ?one green and one red ?to the molecule they want to study. Next, they excite the green dye with a laser. Some of the energy moves from the green dye to the red dye, depending upon the distance between them.

The researchers then measure the brightness of the two dyes simultaneously. The changing ratio of the two intensities indicates the relative movement of the two dyes, and therefore the motion of the molecule or its change in size.

The te chnique revealed intricate details of how RecA nucleates to form a filament, how the filament changes shape, and how the filament removes proteins from DNA.

"Contrary to our initial expectations, both ends of the RecA filament continually grow and shrink, but a higher binding rate at one end causes the filament to grow primarily in one direction," Ha said. "We also learned that as the filament grows and shrinks, it does so by one protein unit at a time."

Following recombination proteins step by step could further help researchers determine in what ways cancer-causing proteins are defective, and perhaps find ways to correct them.


'"/>

Source:University of Illinois at Urbana-Champaign


Related biology news :

1. DNA Recombination and Repair—A New Twist to RecA Function
2. New, automated tool successfully classifies and relates proteins in unprecedented way
3. New binding target for oncogenic viral protein
4. Controversial drug shown to act on brain protein to cut alcohol use
5. Timing is everything: First step in protein building revealed
6. UWs Rosetta software to unlock secrets of many human proteins
7. Researchers find how protein allows insects to detect and respond to pheromones
8. Signaling protein builds bigger, better bones in mice
9. Ancient olfaction protein is shared by many bugs, offering new pest control target
10. Automatic extraction of gene/protein biological functions from biomedical text
11. Discovery of key proteins shape could lead to improved bacterial pneumonia vaccine
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/5/2017)... Today HYPR Corp. , leading innovator ... of the HYPR platform is officially FIDO® Certified ... architecture that empowers biometric authentication across Fortune 500 enterprises ... over 15 million users across the financial services industry, ... product suites and physical access represent a growing portion ...
(Date:4/3/2017)...  Data captured by IsoCode, IsoPlexis Corporation,s ... statistically significant association between the potency of ... objective response of cancer patients post-treatment. The ... cancer patients will respond to CAR-T cell ... to improve both pre-infusion potency testing and cell ...
(Date:3/30/2017)... Trends, opportunities and forecast in this market ... (fingerprint, AFIS, iris recognition, facial recognition, hand geometry, vein ... use industry (government and law enforcement, commercial and retail, ... others), and by region ( North America ... Pacific , and the Rest of the World) ...
Breaking Biology News(10 mins):
(Date:5/24/2017)... ... May 24, 2017 , ... Patient ... developed with Wi-Fi connectivity to reduce the amount of wiring in a healthcare ... addition, compact mobile devices including infusion pumps, heart and hypertension monitoring, glucose monitoring, ...
(Date:5/23/2017)... ... 2017 , ... Firmex today announced the general ... for organizations to send and gather large files and confidential documents beyond the ... size limitations. , Using the same market-tested infrastructure as Firmex’s flagship Virtual ...
(Date:5/23/2017)... ... May 23, 2017 , ... ... source of human cardiovascular cells for research and the development of cardiac ... possible to generate large numbers of cardiomyocytes (hPSC-CMs). Due to varying differentiation ...
(Date:5/23/2017)... ... May 22, 2017 , ... NetDimensions has been ranked as ... Globe™ for Corporate Learning, 2017. , Aragon Research defines Leaders as organizations who ... perform against those strategies. NetDimensions’ ranking as a Leader due to its strengths ...
Breaking Biology Technology: