Scientists have discovered a 22nd amino acid, pyrrolysine. http://cbc.ca/stories/2002/05/24/amino_acid020524 What impact could this have on the study of genetics? I don't see anything really earth-shattering about it, it just seems that we can make even more proteins [as if we needed more Please Register or Log in to view the hidden image! ]. Be gentle, I don't know much about this kinda stuff Please Register or Log in to view the hidden image! .
Welcome aboard Nebula! I wonder how many more amino acids there might be. It's actually like discovering a new element or fundamental particle. So I guess you could say this is very big news. It's very rare I'm sure.
AFAIK this is no real news. Not to the science community anyway. The discovery is not of the amino acid (AA) itself, but rather that this particular amino acid is used. The elementary building block of an AA is NH2-CH-COOH with an R group (essentially any biological group from a simple H to, well anything) connected to the CH group. Since anything can represent R, the different AAs are countless. In the human body, and indeed all animals, only 20 amino acids are used. This 'new' AA is not in animals. What impact will this have on genetics? No idea. Discuss?
It's not that huge a revelation most likely because it is only in one organism right now. It only impacts people who study unusual organisms. Most organisms studied have the normal 20 ... I would have been very surprised if it had taken over another amino acids codon, the fact it was borrowed from a stop is interesting. There is actually a guy at Berkley/UCSF/Caltech (definitely somewhere in cali) who is trying to engineer ways to add new amino acids and used amber stop codons and a read through mechanism to do the similar thing artificially. It would change molecular genetics and molecular biology, but genetics itself was studied before people knew DNA was the substance that carried heritable material or that it was the basis for generating proteins. It is a very abstract discipline far removed from the details.
Well please do allow me to disagree with some of the stuff you folks have been saying. Pyrrolysine is NOT in one organism. It was studied in one organism, Methanosarcina barkeri. Homologs have been found in other organisms in two domains, Bacteria and Archaea. Just because no homolog was discovered in any Eukaryote does not mean that it won't be in the near future. Also, it is NOT true that there are only 20 amino acids translationally encoded in humans. The 21st, selenocysteine is very much found in humans in functional proteins. So this discovery is pretty big. Trust me. I do this for a living.
