Face it, a true appreciation of just how significant this research could ultimately be requires at least a passing understanding of Turing Machines, which of course is all that a ribosome (and on a more philosophical level, each of us) really is. Chemists at New York University have developed a device that allows for the translation of DNA sequences, thereby serving as a factory for assembling the building blocks of new materials. The invention, described in the latest issue of Science magazine, has the potential to develop new synthetic fibers, advance the encryption of information, and improve DNA-based computation.
The device, developed by NYU Chemistry graduate student Shiping Liao and Professor Nadrian C. Seeman, emulates the process by which RNA replicas of DNA sequences are translated to create protein sequences. However, the signals that control the nanomechanical tool are DNA rather than RNA. The dimensions of the machine are approximately 110 x 30 x 2 nm. The device is a machine to make specific DNA sequences by imitating the ribosome’s translational capabilities, said Seeman, who developed the machine with Liao over the last year.
The machine may be set to four different structural settings and allows researchers to determine which elements of a DNA strand are to be used to construct a product sequence. Liao and Seeman employed a pair of PX-JX2 devices—an existing DNA machine developed a few years ago in Seeman’s laboratory—in selecting the DNA molecules and used another DNA motif, known as DX molecules, as an adapter between the strands they carry and the device. The researchers tested the device experimentally by adding a complete set of DX molecules to a solution. The intended DX molecules, which included strands from the target product attached to the device, and the target strands were bonded together, thereby emulating the way RNA molecules code for proteins.
The researchers emphasized that their device does not transcribe the traditional genetic code, but rather, uses an arbitrary code that they made up. However, they noted, its encryption abilities have the potential to construct new types of polymers, which could be used in the production of new synthetic polymer materials. In addition, the machine operation may be used to advance DNA-based computational methods.
Text for this article comes from a NYU press release.
If I remember my biology class right, ribosomes do NOT modify the strands that they are reading. So, they cannot possibly be turing machines.
Oh, and people are not mere turing machines, we are universal machines (turing complete). :)
OK, you’re right, ribosomes are not 100% true turing machines – but you gotta admit, as a microscopic gizmo that literally reads a data tape, they come amazingly close, certainly worthy of being compared to such. Even more amazing to me is that Alan Turing was able to come up with the concept of turing machines in the 1930s BEFORE people had made all of the DNA / ribosome / genetic code breakthroughs of the 1950s and 60s. That’s true brilliance and genius at work.
Too bad homophobia led to the early suicide of this scientific hero.
And yep, I totally agree – mathematically speaking, human beings are indeed turing complete. Which makes them have the (as yet unrealized) power of gods.
… while ribosomes ALONE are not Turing machines, the DNA/RNA/ribosome/cell system as a whole IS literally a turing machine because the ribosome churns out proteins, and a small subset of those proteins DO indeed modify the nucleotide sequence of the DNA data tape. Completion of this feedback loop is technically the minimal requirement for a true turing machine.
Currently this is where evolution comes in. Most if not all of these modifications to existing DNA data tapes are not being commanded by the DNA strand itself – they result as random mutations. “Improvements” to the data tape occur by chance – but they DO occur, and the cellular turing machine has successfully pulled itself up from E. Coli to George W. Bush.
This miniscule random improvement is nothing, of course, compared to what is going to happen when artificial ribosomes, like those in this article engineered by the intelligent design of man, start a new cycle of turing machine improvement on the billions-year-old motif of DNA. I personally believe The Singularity will result, but that rapture of the nerds is a different story…
The problem with humans is that we don’t have infinite memory like a theoretical turing machine. so, we can’t be universal machines because we are not capable of virtualizing any turing machine (even infinite ones) :(