Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Synchrotron Sheds Light On Bacteria’s Solar Cell


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:

More articles from Life Sciences:

nachricht Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences

nachricht Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>