Navigation Links
Structure of RNAi complex now crystal clear
Date:6/20/2012

CAMBRIDGE, Mass. (June 20, 2012) Researchers at the Whitehead Institute and Memorial Sloan-Kettering Cancer Center have defined and analyzed the crystal structure of a yeast Argonaute protein bound to RNA. This complex plays a key role in the RNA interference (RNAi) pathway that silences gene expression. Describing the molecular structure of a eukaryotic Argonaute protein has been a goal of the RNAi field for close to a decade.

"You can learn a lot from biochemical experiments, but to more fully understand a protein like Argonaute, it's useful to know where all of the atoms are and which amino acids are playing important roles," says Whitehead Institute Member David Bartel, who is also an MIT professor of biology and a Howard Hughes Medical Institute (HHMI) investigator. "Learning the Argonaute crystal structure is an important step in understanding the RNAi biochemical pathway and will be the basis for many future experiments."

The yeast Argonaute structure is described in the June 21st print issue of Nature.

In humans and most other eukaryotes, the RNAi pathway can reduce cellular protein production by reducing the proteins' RNA templates. By exploiting this pathway, scientists are able to knock down the expression of specific proteins and thereby determine their roles within the cell or organism. The RNAi pathway has also been of considerable interest for the treatment of human disease.

RNAi depends on two proteins, Dicer and Argonaute. Dicer recognizes double-stranded RNA (dsRNA), latches onto it, and chops it into pieces 21-23 nucleotides long. Argonaute recognizes the dsRNA bits, discards one strand, and uses the other as a guide. When a single-stranded RNA matches the guide RNA's sequence, Argonaute cleaves the targeted RNA, thereby preventing it from serving as a template for protein production.

To determine the structure of Argonaute, Bartel and graduate student David Weinberg partnered with Kotaro Nakanishi in Dinshaw Patel's lab at Sloan-Kettering. Although the team expected to solve the structure of Argonaute alone, they were surprised to find that the protein came along with small bits of RNA that were also observed in the structure. The incorporation of these RNAs had switched the protein into an activated state that contained a four-component active site, the identification of which solved a longstanding mystery of what constituted the "missing" fourth component. With the structure of this complex in hand, scientists now have a better understanding for how it works.

"Seeing the crystal structure of a eukaryotic Argonaute for the first time was very excitingit's such a large protein with a complicated topology and many moving parts," says Weinberg. "It's a really impressive molecular machine."


'/>"/>

Contact: Nicole Giese Rura
rura@wi.mit.edu
617-258-6851
Whitehead Institute for Biomedical Research
Source:Eurekalert

Related biology news :

1. Detector of DNA damage: Structure of a repair factor revealed
2. Study provides new insights into structure of heart muscle fibers
3. CSHL researchers solve structure of human protein critical for silencing genes
4. Psychiatric medication effects on brain structure
5. Mechanical properties and microstructure of cranial and beak bones of the woodpecker and the lark
6. Expedition to undersea mountain yields new information about sub-seafloor structure
7. Autism risk gene linked to differences in brain structure
8. Scientists produce eye structures from human blood-derived stem cells
9. Crystal structure of archael chromatin clarified in new study
10. Studies reveal structure of EV71, a virus causing childhood illnesses
11. A trained palate: Understanding complexities of taste, smell could lead to improved diet
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/16/2017)...   Bridge Patient Portal , an enterprise ... EMR Systems , an electronic medical record solutions ... established a partnership to build an interface between ... Centricity™ products, including Centricity Practice Solution (CPS), Centricity ... new integrations will allow healthcare delivery networks using ...
(Date:4/19/2017)... York , April 19, 2017 ... as its vendor landscape is marked by the presence ... market is however held by five major players - ... Together these companies accounted for nearly 61% of the ... the leading companies in the global military biometrics market ...
(Date:4/13/2017)... SANTA MONICA, Calif. , April 13, 2017 /PRNewswire/ ... New York will feature emerging and ... Innovation Summits. Both Innovation Summits will run alongside the ... variety of speaker sessions, panels and demonstrations focused on ... east coast,s largest advanced design and manufacturing event will ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... Parks Associates announced today that Tom Kerber , Director ... , October 11 in Scottsdale, Arizona . Kerber will ... safety and security products impact the competitive landscape. ... Parks Associates: Smart Home Devices: Main Purchase Driver ... "The residential security market has experienced continued growth, and the introduction of ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... 13 prestigious awards honoring scientists who have made outstanding contributions ... scheduled symposium during Pittcon 2018, the world’s leading conference and exposition for laboratory ...
(Date:10/9/2017)... ... 2017 , ... At its national board meeting in North Carolina, ARCS® ... Departments of Physics and Astronomy, has been selected for membership in ARCS Alumni ... the 2015 Breakthrough Prize in Fundamental physics for the discovery of the accelerating expansion ...
(Date:10/7/2017)... ... October 06, 2017 , ... With ... microscopy and surface analysis, Nanoscience Instruments is now expanding into Analytical Services. ... range of contract analysis services for advanced applications. Services will leverage techniques ...
Breaking Biology Technology: