How bacteria manage stress

Published by  News archive

On 13th Apr 2022

Researchers from the University of East Anglia have identified a new class of enzyme involved in stress management in bacteria.

All organisms, from humans to bacteria, have to be able to respond to a wide range of stresses that result from changes in their environment.

Common amongst these are so called oxidative and nitrosative stresses, which occur when an organism is exposed to high concentrations of reaction oxygen or reactive nitrogen species, respectively. When this happens, fragile component of the cell are damaged, leading to loss of function and, in some cases, cell death.

Unsurprisingly, organisms have evolved a multitude of stress response systems that detect and alleviate particular stresses.

Iron-sulfur clusters, which consist of iron and inorganic sulfur, are found in all cell types where they play essential roles in a wide range of cellular processes. Because they are so reactive, they are often the first cellular components to become damaged under stress conditions.

The di-iron protein YtfE, found widely in bacteria, is generally believed to function directly in the repair of iron-sulfur clusters that have been damaged under stress conditions. This activity has been variably proposed to involve donation of iron for re-building of iron-sulfur clusters, or the removal of nitric oxide (NO) from damaged clusters.

Recently, new evidence came to light from studies of YtfE function in cells that suggested its activity is associated with an increase, and not a decrease, in the concentration of NO. This prompted researchers in the School of Chemistry to re-examine the function of YtfE.

The team, led by Dr Jason Crack and Prof Nick Le Brun, and involving Dr Fraser MacMillan’s lab, as well as researchers from the University of Birmingham and University of Sheffield, have discovered that YtfE is a new type of nitrite reductase enzyme that produces NO.  

They showed that YtfE does not efficiently remove NO from damaged iron-sulfur clusters, nor is it an effective donor of iron for cluster assembly.

The YtfE-catalysed production of toxic NO from nitrite (NO2-) may seem odd, but YtfE is co-regulated with another enzyme, called Hcp, which functions to detoxify NO (via its reduction to nitrous oxide, N2O).

The coupled YtfE/Hcp detoxification pathway represents an effective means by which the cell deals with toxic levels of nitrite that can occur under anaerobic conditions.

The team used a range of approaches, including in vivo genetic and in vitro protein spectroscopy and mass spectrometry, to gain detailed insight into the mechanism by which YtfE generates NO from nitrite.

The work clarifies the role of a protein that has puzzled researchers for a long time, demonstrating that YtfE is a key player for the management of stress under conditions of anaerobic respiration, such as those found in the human gut or when infecting a human host.

The work is published this week in the Journal of the American Chemical Society.

Latest News

  News
A female protestor displays the
19 May 2022

USA slumbers, Europe leads in electoral integrity

The world’s leading democracy is falling behind on electoral integrity, according to new findings from the University of East Anglia (UEA) and the Royal Military...

Read more >
  News
Cranberries held in two hands.
19 May 2022

How cranberries could improve memory and ward off dementia

Adding cranberries to your diet could help improve memory and brain function, and lower ‘bad’ cholesterol – according to new research from the University of East...

Read more >
  News
Surgeons perform heart surgery in an operating theatre.
18 May 2022

Timing of heart surgery crucial, research shows

Valve replacement heart surgery should be performed earlier than conventionally thought for people with aortic stenosis – according to new research from the...

Read more >
  News
16 May 2022

From testing for plastics in teabags to a Q&A with Countrywise’s Liz Bonnin: UEA’s Green Film Festival is back

Following a two-year pandemic hiatus, the Green Film Festival at the University of East Anglia (UEA) is back from Thursday 19 May - Saturday 21 May, offering...

Read more >
Are you searching for something?
  News
16 May 2022

From testing for plastics in teabags to a Q&A with Countrywise’s Liz Bonnin: UEA’s Green Film Festival is back

Following a two-year pandemic hiatus, the Green Film Festival at the University of East Anglia (UEA) is back from Thursday 19 May - Saturday 21 May, offering...

Read more >
  News
A pink pigeon perches on a branch.
13 May 2022

Not all is rosy for the pink pigeon, study finds

The authors of a major study on the once critically endangered pink pigeon say boosting the species’ numbers is not enough to save it from extinction in the future.

Read more >
  News
World of lights with a really bright light shining from Norwich
12 May 2022

UEA’s research confirmed as ‘world-leading’ by national assessment

The global significance and real-world impact of the University of East Anglia’s (UEA’s) research has been confirmed with the Research Excellence Framework 2021...

Read more >
  News
11 May 2022

Innovation & Impact Awards 2022 winners

From saving the world’s animals through socks, improving animal nutrition to sequencing COVID-19 genomes and developing a diagnostic device for dizziness, there...

Read more >
  News
Microplastics on a finger
10 May 2022

How microplastics in the air are polluting the most remote places on earth

Microplastics are being transported to some of the most remote places on earth by the wind, according to new research involving the University of East Anglia.

Read more >
  News
A woman smells a tangerine.
06 May 2022

Research priorities for smell disorders revealed

From stem cell therapy to regenerating smell receptors, experts at the University of East Anglia have helped develop a list of research priorities for people...

Read more >
  News
Secondary School children doing Physics in Design and Technology lesson
06 May 2022

New teaching programme launched to get engineers into teaching Physics

The University of East Anglia (UEA) has been selected by the Department for Education (DfE) to run a new course aimed at getting people from an engineering or...

Read more >