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

 
Microscope view of the monkeypox virus.
23 Sep 2022

Monkeypox outbreak highlights need for One Health approach to prevent future zoonotic diseases

The outbreak of monkeypox is a warning for the adoption of a preventative, One Health, approach, accoding to research from UEA.

Read more >
 
A medical professional helps a young girl in an MRI scanner.
22 Sep 2022

The super-fast MRI scan that could revolutionise heart failure diagnosis

Researchers at the University of East Anglia have developed cutting-edge technology to diagnose patients with heart failure in record time.

Read more >
 
A man in a consultation with a medical professional.
22 Sep 2022

UEA breakthrough reveals how prostate cancer may begin

Researchers at the University of East Anglia have made an important discovery about how prostate cancer may start to develop.

Read more >
 
Protestors holding placards.
20 Sep 2022

‘We’ll turn things upside down!’ Project tracks 420 years of English protest songs 

Read more >
Are you searching for something?
 
Protestors holding placards.
20 Sep 2022

‘We’ll turn things upside down!’ Project tracks 420 years of English protest songs 

Read more >
 
A healthcare professional gives medicine to a patient.
20 Sep 2022

Artificial Intelligence tool could reduce common drug side effects

AI could help clinicians assess which patients are likely to encounter the harmful side effects of some commonly used antidepressants, antihistamines and bladder...

Read more >
 
Ist REF
01 Aug 2022

Thanks from the School of International Development

The School of International Development are delighted to be recently ranked first for overall research quality, impact, environment and outputs in development...

Read more >
 
Hubert Lamb Building
01 Aug 2022

UEA’s Climatic Research Unit turns 50

The realisation that the climate could undergo significant change in the span of a human lifetime was the reason behind the founding of the Climatic Research...

Read more >
 
Sample bottle
01 Aug 2022

The holy grail for taming prostate cancer

UEA researchers have made a crucial link between bacteria and aggressive prostate cancer. Their discovery has the potential to slow or even prevent the...

Read more >
 
Lincoln Barnwell, Prof Jowitt, Dr Redding, Julian Barnwell
01 Aug 2022

UEA to host conference on ‘Norfolk’s Mary Rose’ – The Gloucester

Following the momentous discovery of a royal ship off the Norfolk coast, UEA researchers are fundraising to bring together leading historians to discuss their...

Read more >
 
23 Sep 2022

UEA teacher education partnership celebrates good Ofsted outcome

The University of East Anglia (UEA) Initial Teacher Education (ITE) partnership has received a ‘good’ rating across the board, following an Ofsted inspection of...

Read more >