In Ocean's Depths, Heat-Loving 'Extremophile' Evolves a Strange Molecular Trick

Apr 30, 2009

(PhysOrg.com) -- Making its home near extreme temperatures of thermal vents on the ocean floor, the organism Methanopyrus kandleri harbors a molecular secret that intrigues evolutionary biologists and even HIV researchers.

It turns out that the extremophile M. kandleri contains a mutation that would normally shut down cellular activity, Yale researchers report in the May 1 edition of the journal Science.

The mutation may help the single-cell organism, a member of the Archaea domain, survive in its harsh environment. It may also be an adaptation that combats viruses, which are threats to that live in even the most hostile of environments.

“This exceptional organism provides us with an alternate take on the pathways involved in the production of transfer RNAs. Ultimately this will help us to better understand the diverse processes necessary for protein biosynthesis,” said Dieter Söll, senior author of the paper and Sterling Professor of Molecular Biophysics & Biochemistry as well as Professor of Chemistry

The Yale researchers identified this specific mutation in the genes for 30 different transfer RNAs, which help attach the correct amino acid to protein chains being synthesized inside a cell. At a single location within the transfer RNA molecule of M. kandleri, one of the four nucleotides, a C (cytosine), replaces a U (uracil). This mutation has not been found anywhere else in the transfer RNAs of living cells and, if left uncorrected, could kill the organism.

However, the researchers discovered an enzyme in M. kandleri that converts the mutation back to the standard form and allows the transfer RNA to carry out its work and produce proteins. A crystal structure of the protein, identified by Bradford J. Stanley with his Ph.D. supervisor Yale assistant professor Yong Xiong, reveals how the enzyme might accomplish its essential function.

The newly characterized enzyme functions at the boiling temperature of water. It is a member of the family of so-called cytidine deaminases that mutate DNA and are of great interest to HIV researchers because of their antiviral activity.

“Our enzyme may be of biotechnological interest if we can engineer it to mutate C to U at any desired location within an RNA molecule,” said Lennart Randau, postdoctoral associate in the Söll lab and a lead author of the paper.
Such a potentially damaging mutation must have evolved in M. kandleri for an important reason, said Randau. The scientists speculate that it might be due to the mutation’s role in combating viruses.

Other researchers from Yale involved in the study were Andrew Kohlway and Sarah Mechta.


Join PhysOrg.com on Facebook!
Follow PhysOrg.com on Twitter!

Provided by Yale University (news : web)

Explore further: Engineering a protein to prevent brain damage from toxic agents

add to favorites email to friend print save as pdf

Related Stories

Micro-RNAs Are Life’s Genetic Sculptors

Feb 26, 2009

(PhysOrg.com) -- Yale scientists have found a way to study within a living organism the wonders of micro-RNAs - tiny bits of RNA that act like a sculptor and shape the activity of hundreds of genes. The work ...

Study questions 'cost of complexity' in evolution

Mar 31, 2008

Higher organisms do not have a “cost of complexity” — or slowdown in the evolution of complex traits — according to a report by researchers at Yale and Washington University in Nature.

'Fishy' clue helps establish how proteins evolve

Jan 27, 2009

(PhysOrg.com) -- Three billion years ago, a "new" amino acid was added to the alphabet of 20 that commonly make up proteins in organisms today. Now researchers at Yale and the University of Tokyo have demonstrated ...

Recommended for you

Two teams pave way for advances in 2D materials

31 minutes ago

This month's headlines on two-dimensional polymers showed noteworthy headway. "2-D Polymer Crystals Confirmed At Last," said Chemical & Engineering News. "Engineers Make the World's First Verified, 2-Dimensional P ...

Nature inspires a greener way to make colorful plastics

19 hours ago

Long before humans figured out how to create colors, nature had already perfected the process—think stunning, bright butterfly wings of many different hues, for example. Now scientists are tapping into ...

New catalyst converts carbon dioxide to fuel

21 hours ago

Scientists from the University of Illinois at Chicago have synthesized a catalyst that improves their system for converting waste carbon dioxide into syngas, a precursor of gasoline and other energy-rich products, bringing ...

Bullet 'fingerprints' to help solve crimes

21 hours ago

Criminals don't just have to worry about their own fingerprints these days: because of a young forensic scientist at The University of Western Australia, they should also be very concerned about their bullets' ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

bmcghie
5 / 5 (3) Apr 30, 2009
Really cool stuff. I question how they'll get the enzyme to work at a lower temperature though. Most likely with another newly discovered holoenzyme. Good work, researchers! Thanks, Physorg!
tkjtkj
2.7 / 5 (3) May 01, 2009
I lost count of all the ".. it MAY..do this...." 's

It 'may' turn lead into gold, too.
...er.. or was that 'water into wine'....

Damon_Hastings
not rated yet May 04, 2009
I read through the entire article just to find out how/why such a potentially lethal mutation would have evolved. The article waits until the last sentence to address this, and then only spares a few words to say it might have something to do with combating viruses. I was disappointed that the article never elaborated on this.