Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Synchrotron Sheds Light On Bacteria’s Solar Cell

12.12.2003


Researchers based at the University of Glasgow, using X-ray data collected at the Synchrotron Radiation Source (SRS) at CCLRC Daresbury Laboratory, have made a major advance in our understanding of the process by which sunlight is converted to food energy, without which life on earth could not exist. The work is published this week (12 December 2003) in the journal Science.



Green plants convert the sun’s energy to a usable form in a process called photosynthesis, which ultimately gives us all the oxygen and food we need to survive. Photosynthetic bacteria have evolved to do all this efficiently in a single cell, so they make good model systems. The Glasgow team, led by Professors Richard Cogdell and Neil Isaacs, worked out the structure of the LH1 light-absorbing complex and Reaction Centre that lies at the heart of photosynthesis in the purple bacterium Rhodopseudomonas palustris.

They first isolated and crystallised the intact protein complex from the bacterial cell membrane, then recorded its X-ray diffraction pattern using X-rays generated at the Daresbury synchrotron.‘The highly focused and intense X-ray beam provided at Daresbury was essential for this data collection’, commented Professor Isaacs.


The X-ray data helped to solve a long-standing mystery about the structure of the LH1-RC. Solar energy absorbed by the light harvesting complex is used by the Reaction Centre to power the transfer of electrons across the cell membrane, using a shuttle molecule to carry the electrons. Researchers have been puzzled about how this shuttle molecule gets in and out of the Reaction Centre, which is surrounded by the ring of protein molecules that makes up the LH1. The structure shows that the LH1 ring has a molecular ‘gate’ to enable the shuttle molecule to move freely.

Since 1984 the structures of only 25 membrane proteins have been worked out, compared with around 15,000 soluble ones. ‘Membrane proteins are notoriously difficult to crystallise in the first instance,’ explained Miroslav Papiz, Head of the Biology and Medicine College at Daresbury, ‘and when crystals are obtained they nearly always diffract very weakly. This is why such an intense source of X-rays is needed to study them.’

This work is the third major breakthrough in this fundamental area of biological research to be based on X-ray crystallographic data collected at the SRS. In 1995 the teams of Richard Cogdell and Neil Isaacs at Glasgow, in collaboration with Miroslav Papiz and the Daresbury team, elucidated the structure of another key component of the light-harvesting machinery, the LH2 complex, from the purple bacterium Rhodopseudomonas acidophila. The LH2 complex funnels energy into the LH1 complex. This year the resolution of this structure has been further improved, helping to reveal more details about energy transfer within it.

Meanwhile, in 1997 John Walker from the Laboratory for Molecular Biology in Cambridge was awarded a Nobel Prize for his research on the enzyme responsible for formation of the energy-rich molecule ATP at the end of this energy transfer sequence, based on crystallographic studies done at the SRS in 1995.

Tony Buckley | alfa
Further information:
http://www.clrc.ac.uk

More articles from Life Sciences:

nachricht New application for acoustics helps estimate marine life populations
16.01.2018 | University of California - San Diego

nachricht Unexpected environmental source of methane discovered
16.01.2018 | University of Washington Health Sciences/UW Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Gran Chaco: Biodiversity at High Risk

17.01.2018 | Ecology, The Environment and Conservation

Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials

17.01.2018 | Physics and Astronomy

Fraunhofer HHI receives AIS Technology Innovation Award 2018 for 3D Human Body Reconstruction

17.01.2018 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>