Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stuck on you: scientists lay bare secrets of bacterial attachment proteins

01.09.2004


An unprecedented picture of how bacteria latch on to human cells has been published by UK, French and US scientists. They have produced a finely detailed model of one of the tools used by some of the nastiest varieties of the stomach bug, Escherichia coli, to stick to and gain entry to host cells.



Led by senior author Dr Stephen Matthews, Reader in Chemical and Structural Biology at Imperial College London, the research is published in the latest issue of the journal Molecular Cell (*See Notes to Eds).

Bacteria need to stick to a host cell, before colonising and attacking it, and causing infection. They do this with the help of proteins on their outer surface called adhesins and invasins. The former attaches itself to the host cell and the latter assists the invasion. Together they define how aggressive or virulent the bacteria are at attacking the host.


Most families of adhesins belong to bacteria that cause a single disease, but the ’Dr’ family of Adhesins makes far more trouble: it is responsible for chronic diarrhoeal, intestinal and urinary tract infections, and is similar to some present in strains of Salmonella.

The researchers characterised the way in which the Dr Adhesins help bugs to cause multiple diseases because they use a very common receptor on the host cell membrane as an anchor point to attack. They target a receptor responsible for regulating one of the important human immune responses, known as Decay Acceleration Factor, or DAF.

"Cell adhesion is one of the first contacts between bacteria and host," said Dr Matthews. "Knowing the architecture of the bacteria target allows us to conceive ways to disrupt this adhesion, which may lead to potential therapeutic intervention."

Dr Matthews’ team at Imperial used nuclear magnetic resonance (NMR) spectroscopy to yield detailed insights into the structure of the two nanometre-wide Dr Adhesins.

Their work helps to resolve a long-standing debate amongst microbiologists; it leads to the reclassifying of the Dr Adhesins into a group of bacterial protein appendages known as ’fimbriae’.

These appendages are very difficult to see using the available electron microscopy techniques, and were originally classified as non-fibre or ’afimbrial’.

The new key piece of evidence emerged from some nifty protein engineering of the protein subunit, known as AfaE.

These subunits make up the fibre and cannot fold properly as proteins as they are synthesised with a piece of sequence information missing. In nature, the adjacent subunit possesses this bit of missing information, and ’lends’ it to complete the subunit and build the fibre, in a process known as donor strand complementation.

In the lab, the Imperial team artificially reintroduced the missing protein sequence so that it could complement itself and fold correctly, demonstrating that the fibres assemble in an similar fashion to fimbrial proteins.

The research was principally funded by the Wellcome Trust, and led by the Imperial team with colleagues at the Institut Pasteur, France, the Universities of Edinburgh and Oxford, the University of Texas, Case Western Reserve University, USA, and Adprotech Ltd, UK.

Tom Miller | alfa
Further information:
http://www.imperial.ac.uk

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>