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 Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>