Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Structure of bacterial nanowire protein hints at secrets of conduction: Electrically conducting bacteria important for energy, environment and technology

Zooming in on the Geobacter-Gonorrhea composite shows how the aromatic residues (teal balloon-like structures) bulge from the surface of pilin proteins (variously colored helical structures) within the fiber.
Zooming in on the Geobacter-Gonorrhea composite shows how the aromatic residues (teal balloon-like structures) bulge from the surface of pilin proteins (variously colored helical structures) within the fiber.

Abstract:
Tiny electrical wires protrude from some bacteria and contribute to rock and dirt formation. Researchers studying the protein that makes up one such wire have determined the protein's structure. The finding is important to such diverse fields as producing energy, recycling Earth's carbon and miniaturizing computers.

Structure of bacterial nanowire protein hints at secrets of conduction: Electrically conducting bacteria important for energy, environment and technology

Richland, WA | Posted on November 12th, 2013

"This is the first atomic resolution structure of this protein from an electrically conductive bacterial species, and it sets the foundation for understanding how these nanowires work," said structural biologist Patrick Reardon of the Department of Energy's Pacific Northwest National Laboratory. Reardon is the 2012 William R. Wiley Distinguished Postdoctoral Fellow at EMSL, the DOE's Environmental Molecular Sciences Laboratory at PNNL.

With the help of related structures on disease-causing bacteria, the researchers show that the protein's shape and form suggest possible ways for the bacteria to shuttle electrons along the nanowire. The results were reported in October in the Journal of Biological Chemistry.

"How to get electrons from the inside of bacteria to the outside is important for many different things, such as bacterial fuel cells, how carbon cycles through the environment and how to make new nanomaterials for applications like biocomputers," said Reardon.

Aromatic Therapy

Many bacterial species wave fingerlike projections along their bodies. The bacteria use these fingers, called pili, to adhere to surfaces or weave into films or recognize objects in the environment. A group of related bacteria makes these bendy, stretchy structures out of a protein called pilin, and an even smaller group uses these structures like electrical wires.

Researchers and engineers would like to take advantage of this wiring. Bacteria produce electrons while respiring and use the wires to run electrons out of their little bacterial bodies. Normally the electrons build up or break down minerals in rock, but the system can also be used to clean up toxic heavy metals or to run a bacterial fuel cell.

To better understand how pilins contribute to conduction, Reardon and NMR lead scientist Karl Mueller explored pilin from an electrically conducting bacteria known as Geobacter sulfurreducens.

Previous research on Geobacter's pilin — PilA — provided a big hint. PilA required certain spots along its length known as aromatic residues to conduct electricity. Without those aromatic residues where they were, Geobacter had no zip in its pili.

But proteins are like a long string that folds up into a compact three-dimensional shape. Without knowing the shape of pilin, it wasn't clear where the aromatic residues landed in space or how they contributed to electron shuttling.

Hop or Flow?

To find out, the researchers used NMR — a technology similar to medical MRIs — at EMSL to picture the shape of PilA.

On its own, PilA looks like a long skinny spring, with a slight kink about halfway up. The aromatic residues, which are bulky anyway, bulge along its length. But the protein by itself isn't enough to reveal how conduction works. Many pilin proteins work together to form a fiber, and Reardon and Mueller only had one.

Nor did the researchers have the whole fiber to put into the NMR instrument. To get more clues, Reardon borrowed the computer image of an assembled fiber from an unrelated species, the bacteria that cause gonorrhea. Gonorrhea's fiber does not conduct electricity nor does its pilin have as many aromatic residues. But its pilin has a similar shape to PilA, so using a computer program, Reardon overlaid PilA on its Gonorrhea cousins.

At this point, the aromatic residues clearly stood out.

"We get clusters of aromatic residues, and they wrap along the wire candy cane style," said Reardon.

But that just raised another question. If the electrons traveling along Geobacter's pilin are using these aromatic residues, they could be hopping from aromatic island to aromatic island. Alternatively, the aromatic residues could be close enough to pass the electrons through like a baton in a running race. Reardon and Mueller agree the single structure is not enough to choose between the two options.

The next step, Mueller said, is to purify the whole fiber from Geobacter microbes and determine the complete structure. The task is technologically challenging however because the fiber has to be grown within the bacteria themselves. Visualizing the whole fiber, though, will show the scientists if the fiber resembles islands in a stream more, or the streambed itself.

This work was supported by the Department of Energy's Office of Science.

####

About DOE/Pacific Northwest National Laboratory
Interdisciplinary teams at Pacific Northwest National Laboratory address many of America's most pressing issues in energy, the environment and national security through advances in basic and applied science. Founded in 1965, PNNL employs 4,300 staff and has an annual budget of about $950 million. It is managed by Battelle for the U.S. Department of Energy. For more information, visit the PNNL News Center, or follow PNNL on Facebook, Google+, LinkedIn and Twitter.

EMSL, the Environmental Molecular Sciences Laboratory, is a national scientific user facility sponsored by the Department of Energy's Office of Science. Located at Pacific Northwest National Laboratory in Richland, Wash., EMSL offers an open, collaborative environment for scientific discovery to researchers around the world. Its integrated computational and experimental resources enable researchers to realize important scientific insights and create new technologies. Follow EMSL on Facebook, LinkedIn and Twitter.

The Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.

For more information, please click here

Contacts:
Mary Beckman

509-375-3688

Copyright © DOE/Pacific Northwest National Laboratory

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Reference: Patrick N. Reardon, and Karl T. Mueller. Structure of the Type IVa Major Pilin from the Electrically Conductive Bacterial Nanowires of Geobacter sulfurreducens, J. Biol. Chem. Oct. 11, 2013, DOI: 10.1074/jbc.M113.498527:

Related News Press

News and information

New non-invasive method can detect Alzheimer's disease early: MRI probe technology shows brain toxins in living animals for first time December 22nd, 2014

Piezoelectricity in a 2-D semiconductor: Berkeley Lab researchers discovery of piezoelectricty in molybdenum disulfide holds promise for future MEMS December 22nd, 2014

Quantum physics just got less complicated December 22nd, 2014

Enzyme Biosensor Used for Rapid Measurement of Drug December 22nd, 2014

Laboratories

Piezoelectricity in a 2-D semiconductor: Berkeley Lab researchers discovery of piezoelectricty in molybdenum disulfide holds promise for future MEMS December 22nd, 2014

Student Nanotechnology Laboratories Network Set Up in Iran December 15th, 2014

Unusual Electronic State Found in New Class of Unconventional Superconductors: Finding gives scientists a new group of materials to explore to unlock secrets of some materials' ability to carry current with no energy loss December 8th, 2014

Videos/Movies

“Line dancing bacteria win the 2014 Dolomite and Lab on a Chip Video Competition” December 16th, 2014

Microbullet hits confirm graphene's strength: Rice University lab test material for suitability in body armor, spacecraft protection December 1st, 2014

Govt.-Legislation/Regulation/Funding/Policy

Mysteries of ‘Molecular Machines’ Revealed: Phenix software uses X-ray diffraction spots to produce 3-D image December 22nd, 2014

Piezoelectricity in a 2-D semiconductor: Berkeley Lab researchers discovery of piezoelectricty in molybdenum disulfide holds promise for future MEMS December 22nd, 2014

Atom-thick CCD could capture images: Rice University scientists develop two-dimensional, light-sensitive material December 20th, 2014

Oregon researchers glimpse pathway of sunlight to electricity: Collaboration with Lund University uses modified UO spectroscopy equipment to study 'maze' of connections in photoactive quantum dots December 19th, 2014

Chip Technology

Instant-start computers possible with new breakthrough December 19th, 2014

Switching to spintronics: Berkeley Lab reports on electric field switching of ferromagnetism at room temp December 17th, 2014

Pb islands in a sea of graphene magnetise the material of the future December 16th, 2014

Stanford team combines logic, memory to build a 'high-rise' chip: Today circuit cards are laid out like single-story towns; Futuristic architecture builds layers of logic and memory into skyscraper chips that would be smaller, faster, cheaper -- and taller December 15th, 2014

Discoveries

Mysteries of ‘Molecular Machines’ Revealed: Phenix software uses X-ray diffraction spots to produce 3-D image December 22nd, 2014

New non-invasive method can detect Alzheimer's disease early: MRI probe technology shows brain toxins in living animals for first time December 22nd, 2014

Piezoelectricity in a 2-D semiconductor: Berkeley Lab researchers discovery of piezoelectricty in molybdenum disulfide holds promise for future MEMS December 22nd, 2014

Enzyme Biosensor Used for Rapid Measurement of Drug December 22nd, 2014

Announcements

New non-invasive method can detect Alzheimer's disease early: MRI probe technology shows brain toxins in living animals for first time December 22nd, 2014

Piezoelectricity in a 2-D semiconductor: Berkeley Lab researchers discovery of piezoelectricty in molybdenum disulfide holds promise for future MEMS December 22nd, 2014

Quantum physics just got less complicated December 22nd, 2014

Enzyme Biosensor Used for Rapid Measurement of Drug December 22nd, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

New non-invasive method can detect Alzheimer's disease early: MRI probe technology shows brain toxins in living animals for first time December 22nd, 2014

Piezoelectricity in a 2-D semiconductor: Berkeley Lab researchers discovery of piezoelectricty in molybdenum disulfide holds promise for future MEMS December 22nd, 2014

Quantum physics just got less complicated December 22nd, 2014

Enzyme Biosensor Used for Rapid Measurement of Drug December 22nd, 2014

Environment

Nanoparticles Prove Effective in Removing Phosphor from Calcareous Soil December 10th, 2014

Detecting gases wirelessly and cheaply: New sensor can transmit information on hazardous chemicals or food spoilage to a smartphone December 8th, 2014

Nanocatalysts Can Reduce Pollution Caused by Diesel Engines December 4th, 2014

Green meets nano: Scientists at TU Darmstadt create multifunctional nanotubes using nontoxic materials December 3rd, 2014

Energy

Oregon researchers glimpse pathway of sunlight to electricity: Collaboration with Lund University uses modified UO spectroscopy equipment to study 'maze' of connections in photoactive quantum dots December 19th, 2014

How does enzymatic pretreatment affect the nanostructure and reaction space of lignocellulosic biomass? December 18th, 2014

Iranian Scientists Use Nanotechnology to Increase Power, Energy of Supercapacitors December 18th, 2014

Lifeboat Foundation gives 2014 Guardian Award to Elon Musk December 16th, 2014

Nanobiotechnology

Mysteries of ‘Molecular Machines’ Revealed: Phenix software uses X-ray diffraction spots to produce 3-D image December 22nd, 2014

Scientists trace nanoparticles from plants to caterpillars: Rice University study examines how nanoparticles behave in food chain December 16th, 2014

FEI and Oregon Health & Science University Install a Complete Correlative Microscopy Workflow in Newly Built Collaborative Science Facility December 16th, 2014

UCLA engineers first to detect and measure individual DNA molecules using smartphone microscope December 15th, 2014

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE