Do We Know Of Any Possible Alternatives For Base Pairs In Either Dna Or Rna?

[maddog]

An open question. I was googling around the other day look for alternative to the four Base Pairs that compose RNA & DNA (roughly). I found a few articles where Copper (Cu) as an element could be used as a substitute (I wondered if a metal could be included) for a Hydrogen (H). I did not find any other

specific examples. Are there any? We have

 

A - Adenine

C - Cytosine

G - Guanine

T - Thymine

 

In RNA T can be something else. Are there other Amines that could "theoretically" do similar to what these do? :lightbulb

 

maddog

[maddog]

I remember the name as I thought there were a few - Essential Amino Acids. I vaguely remember there being about twenty or so known (this was over

thirty years ago so now maybe more). I can tell by there names the Base Pairs are also Amino Acids. So what this thread is really asking ---

 

Are there other possible base pairs than the four we use. You are free to think big in I am not requiring that Phosphorus be used necessarily to be the

binding thread. I could be anything with similar behavior to its properties.

 

If so are the constraints in being so (be it Temperature, Pressure, Gravity, etc).

 

I'm just speculating.... ;)

 

maddog

[7DSUSYstrings]

Of course there are Uracil and Methylcytosine, but the bonding energies would be significantly different to confound the normal exchange of free radicals that goes on between the porphyrins and cells. Still, all have a common trait: The molecules of all the RNA-DNA building blocks are massive enough to be replaced by nanoscale electronic devices, for instance a three atom semiconductor could be regulated by single atom resistance and two atom capacitance circuits. Such circuits could exact or recycle a single electron, not unlike a flash drive.

Edited April 17, 2012 by 7DSUSYstrings

[hardy5]

Very Interesting

 

I enjoyed this

[OMICSGroup]

I'll agree with you all.In RNA, Thymine is replaced with Uracil. so Guanine pairs with Cytosine and Adenine pairs with Uracil.

[Bolitoglossa]

Hello Maddog,

 

Let me make a small correction to your second post; bases are not amino acids, they are nucleotides. Amino acids are the building blocks of proteins, and chemically dissimilar to nucleotides. Three bases will code for a specific amino acid to be incorporated into a growing protein chain.

 

The answer to your question is yes - scientists have been able to find alternative base pairs. A very good example is the 7-(2-thienyl)-imidazo[4,5-b]pyridine (Ds) and pyrrole-2-carbaldehyde (Pa) pair, published in Nature Methods in 2006. (Hirao, Ichiro, et al. "An unnatural hydrophobic base pair system: site-specific incorporation of nucleotide analogs into DNA and RNA." Nature Methods 3.9 (2006): 729-735.)

 

 

 

This specific pair will not form hydrogen bonds with each other like the regular bases, but will rather pair through hydrophobic packing.

 

 

You can find other examples in the literature.

 

I am currently working (as an undergrad) in a lab with "unnatural" or "non-canonical" amino acids. We evolve the genetic machinery in ways that allow us to modify the genetic code so that we can genetically incorporate new amino acids not found in nature, giving new useful properties to proteins. It is not necessary to use new base pairs to do this, as we can simply "hijack" some of the codons (there are 64 codons, 61 code for 20 amino acids, 3 codons are "stop" codons, we usually hijack one of the three stop codons, the UAG). However, new base pairs will become very useful once the technology expands.

Edited August 4, 2013 by Nyctanolis