Natural affinities—unrecognized until now—may have set stage for life to ignite

Jul 29, 2013
This is a computer graphic of an RNA molecule. Credit: Richard Feldmann/Wikipedia

The chemical components crucial to the start of life on Earth may have primed and protected each other in never-before-realized ways, according to new research led by University of Washington scientists.

It could mean a simpler scenario for how that first spark of life came about on the planet, according to Sarah Keller, UW professor of chemistry, and Roy Black, UW affiliate professor of bioengineering, both co-authors of a paper published online July 29 in the Proceedings of the National Academy of Sciences.

Scientists have long thought that life started when the right combination of bases and sugars produced self-replicating , or RNA, inside a rudimentary "cell" composed of . Under the right conditions, fatty acids naturally form into bag-like structures similar to today's cell membranes.

In testing one of the fatty acids representative of those found before life began – decanoic acid – the scientists discovered that the four bases in RNA bound more readily to the decanoic acid than did the other seven bases tested.

By concentrating more of the bases and sugar that are the building blocks of RNA, the system would have been primed for the next steps, reactions that led to RNA inside a bag.

"The bag is the easy part. Making RNA from scratch is very hard," Keller said. "If the parts that come together to make RNA happen to preferentially stick to the surfaces of bags, then everything gets easier."

The scientists also discovered a second, mutually reinforcing mechanism: The same bases of RNA that preferentially stuck to the fatty acid also protected the bags from disruptive effects of salty . Salt causes the fatty acid bags to clump together instead of remaining as individual "cells."

The researchers found that several sugars also give protective benefit but the sugar from RNA, ribose, is more effective than glucose or even xylose, a sugar remarkably similar to , except its components are arranged differently. The ability of the building blocks of RNA to stabilize the fatty acid bags simplifies one part of the puzzle of how life started, Keller said.

"Taken together, these findings yield mutually reinforcing mechanisms of adsorption, concentration and stabilization that could have driven the emergence of primitive cells," she said. Roy Black, lead author of the paper, originated the ideas behind the work. A retired biochemist with Amgen Inc., Black contributed funding for the work to Keller's lab – the work also received National Science Foundation funding – and became a UW affiliate professor volunteering in the Keller lab.

"I think that a pretty common story is that some young hotshot comes to UW to start her or his career and does a risky experiment that uncovers new fundamental science," Keller said. "Here we have an older hotshot who came to UW at the end of his Amgen career to do a risky experiment that uncovers new fundamental science.

"I think the story also emphasizes that people don't become scientists just because it is a good job – they do it because they love it," she said. "Roy worked for a year and a half straight, volunteering his time to UW on something he didn't get paid for, just for the joy and the curiosity."

Explore further: Two-armed control of ATR, a master regulator of the DNA damage checkpoint

More information: Nucleobases bind to and stabilize aggregates of a prebiotic amphiphile, providing a viable mechanism for the emergence of protocells, www.pnas.org/cgi/doi/10.1073/pnas.1300963110

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User comments : 12

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PCB
not rated yet Jul 29, 2013
The PNAS link above is bad.
Here is a link to the Washington.Edu page:
http://www.washin...-ignite/
-PC
JVK
1 / 5 (15) Jul 29, 2013
And then... the microRNA/messenger RNA balance was achieved to enable de novo creation of olfactory receptor genes that allowed never-before-required nutrient uptake through the cell membrane that somehow formed and allowed intercellular mechanisms to alter internuclear interactions that are required for ecological, social, neurogenic, and socio-cognitive niche construction. Simply put, life ignited and here we are to explain it all in 300 words or less sans mutations theory or SNPs and amino acid substitutions. Wow! Do you think anything is missing from their correlations, like biological facts, for example?
Murgatroydals
1 / 5 (14) Jul 30, 2013
Science infers how the Creator may have done it.
EnricM
2.4 / 5 (12) Jul 30, 2013
Science infers how the Creator may have done it.


Sorry, but for Kreator you better check our Metal-Archives.org, this blog is about Science not about Heavy Metal. Sorry mate, I'm also a big fan of Teutonic Thrash... \m/
antialias_physorg
3.9 / 5 (13) Jul 30, 2013
I think the story also emphasizes that people don't become scientists just because it is a good job – they do it because they love it," she said. "Roy worked for a year and a half straight, volunteering his time to UW on something he didn't get paid for, just for the joy and the curiosity.

To all you nutcases out there who think there is some sort of science conspiracy in the world:
Read this.
Read it again.
Then read it again.
Then realize that this is THE scientific mindset (even though you may never understand how someone can have such a mindest - but then again you don't need to understand it. You'll never be scientists, after all)
antialias_physorg
3.1 / 5 (9) Jul 30, 2013
The dictators and drug dealers love their job too in the same way, like the Hitler did

Dictators don't love the job. They love the power and money that comes with the job (same as drug dealers). If money and power could be gotten easier another way they wouldn't be dictators (or drug dealers) but that.

Scientists love the science. There's just nothing else that will give you that level of fun and feeling of actually doing something worthwhile (on a grander level than mere petty self-absorbed desires).

The scientists often forget, they're payed with tax payers for bringing of progress, not for their job love.

Even scientists need to eat. However ROI on science is by far better than any other investment you care to name (with the possible exception of illegal drugs)

And scientists can earn a LOT more in the industry doing boring R&D (believe me, I know, Oh how I wish I didn't). It certainly isn't the huge salary in research they're after.
Gmr
3 / 5 (8) Jul 30, 2013
Wow. From a love of science and a spirit of discovery, wonder and dedication to Hitler in nothing flat. Transparent agenda much?

That nonsense aside, this makes a lot of sense to me that you could have populations of chemistry that essentially can increase collectively the survival of chemicals and structures that each individually would find it hard to do. You could probably run experiments similar to this for extended durations and see what you get. Daily temperature and light fluctuation plus tidal action ( periodic agitation and/or partial dessication ) Sounds like fun science to me. I love emergent phenomena.
Gmr
2.1 / 5 (7) Jul 30, 2013
Science infers how the Creator may have done it.

Yeah, invisible and with an angelic proxy - and as Mary could attest, without protection...
Thnder
1 / 5 (1) Jul 31, 2013
The scientists often forget, they're payed with tax payers for bringing of progress for human civilization - not for their job love. .


Roy worked for a year and a half straight, volunteering his time to UW on something he didn't get paid for, just for the joy and the curiosity.


Somebody forgot to remind Roy. He apparently forgot to get paid.
Torbjorn_Larsson_OM
5 / 5 (1) Aug 01, 2013
Wow, I didn't think I would see they day where there was a prediction of "why those 4 bases". But I'm happy to be wrong.

I am less happy with the prediction of "why ribose", since RNA is uniquely suited to predict how metabolic function (ribozymes) and genetic function (mRNA) came together. The iron/anoxic world theory just tested that conserved one electron enzymatic function uniquely remains in tRNA and rRNA. But of course it can't hurt if RNA was selected also, perhaps already, at the lipid membrane stage of alkaline hydrothermal vents (our phylogenetic cousins).

And I am least happy with the 3 trolls that surface as comment 3&4&7, and display their total ignorance of biology and analysis to boot. "No evolution (JVK)", "religious magic (M)", "argumentum ad hitlerum (T)". Really?
antialias_physorg
2.6 / 5 (5) Aug 01, 2013
Wow, I didn't think I would see they day where there was a prediction of "why those 4 bases". But I'm happy to be wrong.

I think an interesting question will be: under what conditions could there be other bases? Seems to me that a different concentration process might have lead to a different set of bases...which may or may not have also been a possible start to life.

It's a fascinating way to look at starting conditions anew and may shift the probabilies of life evolving at all on any given planet vastly upwards (certainly the fact that life started off so early in the history of the planet is a clue - though no proof - that life starts off easily).
velvetnoose
not rated yet Aug 02, 2013
Seem's highly logical... My kind of party.

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