Navigation Links
Brown scientists map structure of DNA-doctoring protein complex

More than half of the human genome is made up of bits of mobile DNA, which can travel inside the body and insert genes into the chromosomes of target cells. This DNA doctoring not only shapes species over time, it also spreads antibiotic resistance and is used by bacteria that spread Lyme disease and by viruses linked to certain forms of cancer.

Last year in Nature, scientists working in the Brown University lab of Arthur Landy and the Harvard Medical School lab of Thomas Ellenberger announced they had solved the structure of "-integrase ("-Int), the protein "surgeon" that allows mobile DNA to cut into a chromosome, insert its own genes, and then sew the chromosome back up. That work was conducted using the lambda virus, which infects Escherichia coli (E. coli) bacteria and serves as a model that scientists use to understand mobile DNA.

Now scientists in the Landy lab have solved the structure of a DNA-protein complex that acts as a team of "nurses," aiding "-Int during this snip-and-solder procedure known as site-specific recombination. The structure is a three-dimensional representation of the DNA within this complex. Pictured on the cover of the Nov. 17, 2006, journal Molecular Cell, it looks like DNA dressed for a party, a double helix decked with clumps of curly, colorful ribbon. By solving this structure, scientists now know how these six proteins interact with each other and fold DNA during site-specific recombination.

"Once you know how these proteins and DNA are arranged, you have a much better sense of their function," said Xingmin Sun, a postdoctoral research associate in the Landy lab and the lead author of the journal article. "And once you know their function, you begin to see how the real work inside cells gets done."

Sun said solving the structure of the DNA-protein complex called for some creativity. Because it is a string of six proteins, the complex is too big and too f lexible to analyze through standard methods such as X-ray crystallography.

Sun used fluorescence resonance energy transfer or FRET, a technique typically used to study small protein complexes in a solution. This time, Sun used FRET to study large protein complexes in a gel. He tagged the DNA with fluorescent dyes and purified the proteins, placing them in a gel that was then shot through with light. Sun measured the wavelengths of light as they bounced between the molecules of dye. Those measurements were then fed into a special software program created by Dale Mierke, a Brown professor of medical science, which plotted their positions to create the structural map.

"The real breakthrough here is successfully using FRET to determine the structure of a large protein-DNA complex," Sun said. "Biologists now have a new tool to help them understand a variety of these complexes, including ones that control cell division, gene expression and DNA replication. So this technique represents a big advance."
'"/>

Source:Brown University


Related biology news :

1. Brown-Harvard team solves mobile DNAs surgical sleight-of-hand
2. Prions rapidly remodel good protein into bad, Brown study shows
3. Brown seaweed contains promising fat fighter, weight reducer
4. Brown team finds crucial protein role in deadly prion spread
5. Brown cancer biologists identify major player in cell growth
6. Bones in motion: Brown scientists to create new 3-D X-ray system
7. Wisconsin scientists grow critical nerve cells
8. UCSB scientists probe sea floor venting to gain understanding of early life on Earth
9. UAB scientists discover the origin of a mysterious physical force
10. Fox Chase Cancer Center scientists identify immune-system mutation
11. Weizmann Institute scientists develop a new approach for directing treatment to metastasized prostate cancer in the bones.

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:2/27/2017)... 27, 2017   Strategic Cyber Ventures , the ... led a $3.5 million investment in  Polarity , the ... Ventures is DC based and is led by cybersecurity ... . Ron Gula , also a longtime cybersecurity ... in this series A round of funding. This new ...
(Date:2/21/2017)... , February 21, 2017 ... 70 Millionen US-Dollar wachsen. Nach einem Gespräch mit mehr als ... einige Hindernisse zu überwinden gilt, um diese Prognose zu ... ... anderem die Mobilisierung der finanziellen Mittel für die Biobank, ...
(Date:2/10/2017)... , Feb 10, 2017 Research ... report "Personalized Medicine - Scientific and Commercial Aspects" ... ... medicine. Diagnosis is integrated with therapy for selection of treatment ... early detection and prevention of disease in modern medicine. Biochip/microarray ...
Breaking Biology News(10 mins):
(Date:3/23/2017)... March 23, 2017  SeraCare Life Sciences, ... in vitro diagnostics manufacturers and clinical laboratories, ... first multiplexed Inherited Cancer reference material ... by next-generation sequencing (NGS). The Seraseq™ Inherited Cancer ... input from industry experts to validate the ...
(Date:3/23/2017)... ... March 23, 2017 , ... Ellen ... the Connecticut Technology Council (CTC) as a 2017 Women of Innovation® finalist. Matloff ... of Innovation Awards Dinner. , The dinner recognizes women accomplished in science, technology, ...
(Date:3/23/2017)... 2017 According to a report by Transparency ... fragmented due to the presence of a large pool of participants; ... Fisher , and Sigma-Aldrich, compete with each other in this market. ... more than 76% of this market in 2016.  ... As of now, a large number ...
(Date:3/23/2017)... (PRWEB) , ... March 23, 2017 , ... ... monitoring solutions, today announced the hire of Dr. Sigmund “Sig” Floyd as Vice ... applications, strategic partnerships and joint development activities. , “Dr. Floyd’s career has spanned ...
Breaking Biology Technology: