Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

’Knot’ to be undone, researchers discover unusual protein structure

27.11.2002


Researchers funded by the National Institute of General Medical Sciences have determined the structure of a protein with a surprising feature in it: a knot. This is the first time a knot has been found in a protein from the most ancient type of single-celled organism, an archaebacterium, and one of only a few times a knot has been seen in any protein structure.



This very unusual protein shape finding is a result from the NIGMS Protein Structure Initiative, a 10-year effort to determine 10,000 unique protein structures using fast, highly automated methods. NIGMS, a component of the U.S. Department of Health and Human Services’ National Institutes of Health, provides $50 million per year to nine PSI research centers. The protein knot structure was solved at one of the PSI centers, the Midwest Center for Structural Genomics, which is directed by Andrzej Joachimiak, Ph.D., of Argonne National Laboratory in suburban Chicago.

The researchers describe the new protein structure in the journal Proteins. Their article will be published online Nov. 27 and in print in early December.


"It’s a surprising and different structure," said NIGMS’ John Norvell, Ph.D., director of the Protein Structure Initiative. Protein folding theory previously held that forming a knot was beyond the ability of a protein. Joachimiak suggests that the newly discovered knot may stabilize the amino acid subunits of the protein.

Such discoveries are just what the PSI aims for. "The PSI approach is to solve thousands of unique protein structures," said Norvell. "It’s a discovery-driven effort, a voyage into the unknown. We aren’t sure what we’ll find, but we expect to map a great diversity of protein structures."

"This makes us want to find out why nature goes to the trouble of creating a knot instead of a more typical fold," said Joachimiak.

One of the main goals of the PSI is to understand all of the possible shapes of proteins in nature. Scientists hope that understanding the full range of protein shapes will shed light on the mysterious process proteins use to fold into a three-dimensional structure from a linear chain of amino acid subunits. Ideally, scientists would like to be able to predict the shape of a protein from the sequence of the gene that codes for it. This ability could be immensely useful in understanding diseases and developing new drugs because a protein’s shape offers big clues to its function and can point to ways of controlling that function.

The "high-throughput" PSI approach is radically different from how scientists have approached protein structure determination in the past. Until recently, scientists focused on solving the structures of proteins with known functions.

The newly discovered knotted protein comes from a microorganism called Methanobacterium thermoautotrophicum. This organism is of interest to industry for its ability to break down waste products and produce methane gas. Scientists know which gene codes for the 268-amino acid protein, but they do not know the protein’s function. They speculate that it binds to RNA, a chemical cousin of the genetic material DNA, and helps process this molecule.

The PSI, currently in its pilot phase, expects to move into production phase by the end of 2005. By the end of the pilot phase, each center will aim to produce 100 to 200 new protein structures per year, adding greatly to the number of known structures. The PSI also expects to dramatically lower the average cost of solving a structure.

The paper describing the new structure was authored by scientists at Argonne National Laboratory and the University of Toronto. The nation’s first national laboratory, Argonne conducts basic and applied scientific research across a wide spectrum of disciplines, ranging from high-energy physics to climatology and biotechnology. The laboratory is operated by the University of Chicago as part of the U.S. Department of Energy’s national laboratory system.


NIGMS supports basic biomedical research and training nationwide. NIGMS-funded studies lay the foundation for advances in disease diagnosis, treatment and prevention. To learn more, visit the NIGMS Web site at www.nigms.nih.gov.

For information about the protein knot, contact Linda Joy in the NIGMS Office of Communications and Public Liaison at 301-496-7301 to speak with PSI director John Norvell, Ph.D, or Catherine Foster of Argonne National Laboratory at 630-252-5580 to speak with Andrzej Joachimiak, Ph.D.

REFERENCE

Zarembinski TI, Kim Y, Peterson K, Christendat D, Kharamsi A, Arrowsmith CH, Edwards AM, Joachimiak A. Deep trefoil knot implicated in RNA binding found in an archaebacterial protein. Proteins 2002; 50: 177-183.


Linda Joy | EurekAlert!
Further information:
http://www.nih.gov/nigms

More articles from Health and Medicine:

nachricht Study shows novel protein plays role in bacterial vaginosis
13.12.2019 | University of Arizona Health Sciences

nachricht Illinois team develops first of a kind in-vitro 3D neural tissue model
12.12.2019 | University of Illinois College of Engineering

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Virus multiplication in 3D

Vaccinia viruses serve as a vaccine against human smallpox and as the basis of new cancer therapies. Two studies now provide fascinating insights into their unusual propagation strategy at the atomic level.

For viruses to multiply, they usually need the support of the cells they infect. In many cases, only in their host’s nucleus can they find the machines,...

Im Focus: Cheers! Maxwell's electromagnetism extended to smaller scales

More than one hundred and fifty years have passed since the publication of James Clerk Maxwell's "A Dynamical Theory of the Electromagnetic Field" (1865). What would our lives be without this publication?

It is difficult to imagine, as this treatise revolutionized our fundamental understanding of electric fields, magnetic fields, and light. The twenty original...

Im Focus: Highly charged ion paves the way towards new physics

In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.

Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...

Im Focus: Ultrafast stimulated emission microscopy of single nanocrystals in Science

The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.

Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...

Im Focus: How to induce magnetism in graphene

Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Supporting structures of wind turbines contribute to wind farm blockage effect

13.12.2019 | Physics and Astronomy

Chinese team makes nanoscopy breakthrough

13.12.2019 | Physics and Astronomy

Tiny quantum sensors watch materials transform under pressure

13.12.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>