[HN Gopher] Qt45: A small polymerase ribozyme that can synthesiz...
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Qt45: A small polymerase ribozyme that can synthesize itself
Author : ppnpm
Score : 111 points
Date : 2026-02-27 23:42 UTC (23 hours ago)
(HTM) web link (www.science.org)
(TXT) w3m dump (www.science.org)
| java-man wrote:
| 2009 paper: Self-sustained replication of an RNA enzyme [0].
|
| [0] https://pubmed.ncbi.nlm.nih.gov/19131595/
| rcyeh wrote:
| Amazing! The 2009 Lincoln & Joyce paper you cited catalyzes one
| bond per hour on average. (Doubling time = 1 hour, but only one
| bond between oligonucleotides needed to double.)
|
| OP's Gianni et al 2026 paper connects 45 nucleotides, taking 72
| days (1700 hours) to yield 0.2%.
|
| The latter effort is like drawing the whole owl.
|
| That is incredible patience. Without access to the full
| article, I read only the abstract. I wonder if they used
| simulations to narrow the candidates?
| java-man wrote:
| https://pmc.ncbi.nlm.nih.gov/articles/PMC7618777/pdf/EMS2125.
| ..
| Noumenon72 wrote:
| I don't know if ChatGPT translated your rate for the 2026
| paper right, but it says you mean:
|
| * 99.8% of the starting molecules fail to form the desired
| product
|
| * The ones that do, form 0.026 bonds per hour
| cyberax wrote:
| It's interesting, that we're getting down to the sizes of self-
| replicating RNA that realistically can form by a complete
| accident.
|
| Getting this sequence by random chance out of a pile of
| nucleotides is a 1 in 2^90 chance. That's around 1.2*10^27 or
| just around 20000 moles! Not at all an impossible number.
| jjk166 wrote:
| Note that the Bennu asteroid sample had approximately 5
| nanomoles of nucleotides per gram, meaning 20,000 moles of
| nucleotides could be delivered by a single 4 million ton
| asteroid, which if it were a spherical carbonaceous chondrite
| would be about 183 meters in diameter. An asteroid about that
| size impacts earth roughly every 36,000 years, and that mass of
| meteor material falls to earth each century.
|
| If primordial earth's oceans had nucleotide concentrations
| comparable to Bennu, then there would be about 10^39
| nucleotides in the ocean.
| nkrisc wrote:
| If raw materials isn't the bottle neck for life every where,
| then what might it further down the line between oceans full
| of nucleotides and life? The oceans themselves?
| cousinbryce wrote:
| Temperature range and magnetic field are my first thoughts.
| dekhn wrote:
| I don't see any reason for the source molecules to come from
| space. We already know that nucleotides will spontaneously
| form and polymerize in conditions consistent with the early
| earth, and a meteorite origin just moves the source of those
| nucleotides elsewhere but doesn't answer how they formed.
| rolph wrote:
| space has been around for a lot longer than earth, its
| possible that inter planetary generation of nucleic acids
| may be primarily a matter of chemistry.
|
| Nucleobase synthesis in interstellar ices[2019]
|
| https://www.nature.com/articles/s41467-019-12404-1?error=se
| r...
|
| Chemistry of Abiotic Nucleotide Synthesis[2020]
|
| https://pubs.acs.org/doi/10.1021/acs.chemrev.9b00546
| heavyset_go wrote:
| It's possible (proto-)life evolved in the pre-Earth
| protoplanetary disk.
|
| If so, life might not require a special snowflake planet
| like Earth to develop. Development could be solar system-
| wide, and common in other early solar systems.
| jjk166 wrote:
| Delivery by meteorites isn't necessarily the only or even
| primary source, but the fact is that it is a source we can
| directly observe, and it is a sufficient source. Earth's
| primordial chemistry likely did create more, but the
| existence of those conditions is theoretical, and such
| additional production need not be invoked to explain the
| needed level of abundance. Even a world with very different
| conditions from primordial Earth would likewise receive
| vast quantities of nucleotide during its formation and
| continuous replenishment afterwards.
| littlestymaar wrote:
| I wonder how much nucleotides present in asteroids in space
| survive the massive heating in the atmosphere and the crash
| though.
| Paedor wrote:
| 20000 moles of length 45 nucleotides is 306 metric tons? Spread
| out over millions of years, that does seem completely feasible.
| adgjlsfhk1 wrote:
| it's much more than 1 in 2^90. this specific 45 base sequence
| was found by random search which strongly implies that the odds
| of finding such a protein are much much higher (i.e. >2^-30)
| since the experiment probably only searched a couple million
| proteins
| cyberax wrote:
| (these are not proteins, these are RNA sequences)
|
| And it's likely that there are even smaller replicators but
| probably not much smaller. And there are likely more
| configurations among these 45 base-combinations that can
| self-replicate. It's also more likely that the first
| replicators were arrangements of multiple smaller molecules
| that can amplify themselves, and not just one large molecule.
|
| But even this longer sequence is well within the realm of
| synthesis by pure chance. RNA molecules can grow base-by-
| base, so a random walk model should eventually produce it.
| Kotlopou wrote:
| Actually, the search here is chemical -- you make a bunch of
| random small RNA sequences, then chemically replicate those
| that do what you want, and after a few cycles of this you
| find just a few sequences dominating the population. The
| pools can easily reach 10^14 examples and more, because you
| don't need a separate container/experiment for each one, but
| do it all together in one batch. The keyword is SELEX, a
| pretty cool idea: https://en.wikipedia.org/wiki/Systematic_ev
| olution_of_ligand...
| dekhn wrote:
| See also: Spiegleman's Monster
| panarchy wrote:
| Quinozyme
| guax wrote:
| We haven't finished migrating from Qt5 and there is a v45
| already? Jeez.
| pcrh wrote:
| The pay wall doesn't permit much access to the details of this. A
| better summary is available at the UK's MRC website, link below.
|
| https://mrclmb.ac.uk/news-events/articles/bridging-the-gap-f...
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