Navigation Links
New study sheds light on evolutionary origin of oxygen-based cellular respiration
Date:1/22/2012

Researchers at the RIKEN SPring-8 Center in Harima, Japan have clarified the crystal structure of quinol dependent nitric oxide reductase (qNOR), a bacterial enzyme that offers clues on the origins of our earliest oxygen-breathing ancestors. In addition to their importance to fundamental science, the findings provide key insights into the production of nitrogen oxide, an ozone-depleting and greenhouse gas hundreds of times more potent than carbon dioxide.

As the central process by which cells capture and store the chemical energy they need to survive, cellular respiration is essential to all life on this planet. While most of us are familiar with one form of respiration, whereby oxygen is used to transform nutrients into molecules of adenosine triphosphate (ATP) for use as energy ("aerobic respiration"), many of the world's organisms breathe in a different way. At the bottom of the ocean and in other places with no oxygen, organisms get their energy instead using substances such as nitrate or sulfur to synthesize ATP, much the way organisms did many billions of years ago ("anaerobic respiration").

While less well-known, this latter type of cellular respiration is no less important, fuelling the production of most of the world's nitrous oxide (N2O), an ozone depleting and greenhouse gas 310 times more potent than carbon dioxide. As the enzyme responsible for catalyzing the reactions underlying anaerobic respiration, nitric oxide reductase (NOR) has attracted increasing attention in environmental circles. The mystery of NOR's catalyzing mechanism, however which accounts for a staggering 70% of the planet's N2O production remains largely unsolved.

With their latest research, the team sought an answer to this mystery in the origin of an evolutionary innovation known as the "proton pump". To accelerate ATP-synthesis, aerobic organisms harness the potential of an electrochemical concentration gradient across the cell, created by "pumping" protons out using energy from an oxygen reduction reaction. The enzyme powering this mechanism, cytochrome oxidase (COX), is genetically and structurally similar to NOR, suggesting a common ancestor. No evidence of any "pump", however, has been detected in anaerobic organisms.

That is, until now. Using radiation from the RIKEN SPring-8 facility in Harima, Japan, the world's largest synchrotron radiation facility, the researchers probed the 3D structure of qNOR and discovered a channel acting as a proton transfer pathway for a key catalytic reaction. While not itself a proton pump, the position and function of this pathway suggest it is an ancestor of the proton pump found in COX. The finding thus establishes first-ever evidence for a proton pump in anaerobic organisms, shedding light onto the mysterious mechanisms governing the production of nitrogen oxide and the evolutionary path that led to their emergence.


'/>"/>

Contact: RIKEN Global Relations Office
gro-pr@riken.jp
RIKEN
Source:Eurekalert  

Related biology news :

1. Long-term study shows effect of climate change on animal diversity
2. £2 million study to reveal workings of dementia genes
3. New study looks to define evangelicals and how they affect polling
4. CU-Boulder study suggests air quality regulations miss key pollutants
5. Researchers study acoustic communication in deep-sea fish
6. Study reveals homeowner perceptions in fire-prone areas
7. Researchers study how pistachios may improve heart health
8. Study: urban black bears live fast, die young
9. New study indicates link between weight gains during pregnancy and dieting history
10. Study reveals specific gene in adolescent men with delinquent peers
11. Sweat it out: UH study examines ability of sweat patches to monitor bone loss
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
New study sheds light on evolutionary origin of oxygen-based cellular respiration
(Date:4/26/2016)... DUBLIN , April 27, 2016 ... of the  "Global Multi-modal Biometrics Market 2016-2020"  report ... ) , The analysts forecast ... a CAGR of 15.49% during the period 2016-2020.  ... a number of sectors such as the healthcare, ...
(Date:4/14/2016)... 2016 BioCatch ™, the ... announced the appointment of Eyal Goldwerger as ... Goldwerger,s leadership appointment comes at a time of ... deployment of its platform at several of the world,s ... discerns unique cognitive and physiological factors, is a winner ...
(Date:3/29/2016)... 2016 LegacyXChange, Inc. (OTC: ... SelectaDNA/CSI Protect are pleased to announce our successful effort ... variety of writing instruments, ensuring athletes signatures against counterfeiting ... from athletes on LegacyXChange will be assured of ongoing ... Bill Bollander , CEO states, "By ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... June 24, 2016 Epic Sciences unveiled ... cancers susceptible to PARP inhibitors by targeting homologous ... (CTCs). The new test has already been incorporated ... multiple cancer types. Over 230 clinical ... response pathways, including PARP, ATM, ATR, DNA-PK and ...
(Date:6/23/2016)... ... June 23, 2016 , ... UAS LifeSciences, one ... of their brand, UP4™ Probiotics, into Target stores nationwide. The company, which has ... add Target to its list of well-respected retailers. This list includes such fine ...
(Date:6/23/2016)... 2016 Houston Methodist Willowbrook Hospital has ... Association to serve as their official health care ... Willowbrook will provide sponsorship support, athletic training services, ... coaches, volunteers, athletes and families. "We ... Association and to bring Houston Methodist quality services ...
(Date:6/23/2016)... FRANCISCO , June 23, 2016   EpiBiome ... has secured $1 million in debt financing from Silicon ... ramp up automation and to advance its drug development ... its new facility. "SVB has been an ... beyond the services a traditional bank would provide," said ...
Breaking Biology Technology: