Scientists Create Synthesized DNA Bases

Iddo Genuth writes to tell us that researchers at the Scripps Research Institute in San Diego have created two artificial DNA bases in an effort to "expand biology's potential." "In the future, [chemist Floyd] Romesberg envisions manipulating the genetic code of bacteria in order to assemble better drugs or even man-made proteins. Until now, the bases only work in bacteria, so human augmentation is currently not possible. Another option is to use alpha and beta to help construct nanomachines to be used for drug delivery. 'This is like jumping from the Stone Age to the Bronze Age,' Romesberg says. 'It takes time to figure out how best to use metal.'" Update 18:10 GMT by SM: Roger writes to share the NewScientist link with a bit more information. There is also the original release text for consideration.

Comments

I want my Vitamin C!

[snowgirl]

Can we get back our Vitamin C gene again? I would love being able to eat less fruit... Scurvy sucks.

Re:I want my Vitamin C!

[twatter]

This has implications beyond the delivery of drugs. Drugs act at the protein level, but imagine a delivery mechanism that does not require a protein receptor, but instead acts at the DNA filament level.

This is HUGE news.

Re:I want my Vitamin C!

[jollyreaper]

Can we get back our Vitamin C gene again? I would love being able to eat less fruit... Scurvy sucks.

Have you ever tried coconut rum and fresh OJ? You'll never bitch about drinking your fruits again.

Re:I want my Vitamin C!

[ShieldW0lf]

If it hasn't been sprayed through a pile of burning rotten vegetation from Scotland, it's shite.

Follow the link at the end of the article

[Sir_Real]

There is a more technical explanation in the link at the end of the article.

These are bases not amino acids

[NFN_NLN]

He's adding new bases which have no coding to amino acids. I don't see the purpose of this. Is it just for adding a trace or marker in DNA?

All the bases do are code for amino acids and it's the amino acid sequence which accounts for a protein's shape. In the end it's the protein's shape that matters for chemical interactions.

Re:These are bases not amino acids

[olyar]

Mostly they just want to be able to write a technical paper called "All your base (pairs) are belong to us".

Re:These are bases not amino acids

[Robert1]

You're totally right. This is such a non-story and frankly mildly offensive in how full of himself the scientist is with sweeping comments like that.

As it stands currently, the amount of genetic degenerecy in amino acid coding means that they would easily have those double and tripled coded amino acids switched to something else. They could potentially add another 20-30 new amino acids with absolutely no change in the number or form of the base pairs used.

Its like finding a solution to a problem that doesn't exist, will never exist, and serves no purpose even if it was found. But apparently its equivalent from going to the iron age from the bronze age. Ha!

Re:These are bases not amino acids

[Anonymous Coward]

Yeah, while the science here is kind of neat, it's not the biggest news in the world. The article title does not at all reflect what's newsworthy here, anyway. Scientists have been creating synthetic and/or modified nucleotides for decades and successfully incorporating them in to DNA and RNA. The news is that they found a synthetic base that can be copied by DNA polymerase. This is the enzyme that copies your DNA, putting an A next to a T on the opposite strand, a C opposite a G, a T opposite an A, and a G opposite a C. DNA polymerase will now put their new base, 3FB, opposite another 3FB on the opposite strand, and they set up some directed evolution to screen for mutant polymerases that will do a better job of it.

This is kind of neat, but the medical applications of this are pretty limited. First of all, it's unclear if RNA polymerase is able to perform the same reaction, or if only DNA polymerase can. If RNA polymerase can't insert a 3FB base opposite a 3FB base, then this news will basically go nowhere. An expanded genetic code is useless if it's confined to DNA only. The information in the DNA has to get into the RNA before protein can be synthesized, and it takes an RNA polymerase that can insert 3FB in order to do that.

However, even if RNA polymerase or a mutant will perform that addition, there's currently no use for it. There are no natural tRNAs that will pair with a codon containing 3FB, and even if you add some 3FB-containing tRNA genes to an organism, you still have to get an amino-acylation enzyme to strap an amino acid to that tRNA (not a trivial thing), and if you do, it'd have to be a novel amino acid to really mean something. Otherwise, you've just found an extremely difficult way of doing what could have been done with the machinery that's already in place.

This is kind of cool and all, but if Slashdot posted an article every time some scientist found a non-natural function of a given enzyme, it'd completely drown out all the articles hating on the RIAA, and we can't have that.

Re:These are bases not amino acids

[Atmchicago]

All the bases do are code for amino acids

That's actually not true. A lot of DNA bases are important in mediating binding to proteins, such as RNA or DNA polymerase, histones, etc. Other bases are important in RNA-based regulator mechanisms, such as anti-terminators.

So the truth is that although we can't really say what we can do with these extra bases right now, the possibilities extend way beyond making new proteins and have many implications for regulation. Why is regulation important? Because differential gene expression is the fundamental principle that allows for cell differentiation and mediating responses to external change.

And for the record, IAAB (I am a biologist).

Still missing critical information

[Raul654]

For those of you who forgot your biology, 3 DNA consecutive DNA base pairs (called a codon) are translated into a single amino acid. (Khorana, Holley and Nirenberg won the 1968 Noble prize in medicine for figuring this out and determining the mapping from base pairs to amino acids)

So, after reading the technical article, it says that DNA polymerase can bind to the new base pairs (allowing it to replicate), but it doesn't say what amino acids (if any) these new base pairs code for. That's important information because this alleged breakthrough is useless if it doesn't so something useful where proteins are concerned.

Re:I for one...

[eviloverlordx]

The Island of Dr. Moreau called; they want their genetic manipulation with unintended consequences back. I told the caller to take a number.

Old News

[dwye]

We have seen this before. The new bases just make new STOP codons, until someone creates new types of MRNA and/or TRNA to let the mitochondria process them to add a matching amino acid.

Where is the whatcanpossiblygowrong tag, like last time? Have the Luddites left, already?

Bronze Age

[wcrowe]

'It takes time to figure out how best to use metal.'

I don't think it took too much time to figure out that the best use of bronze was to make it sharp and run someone through with it.