02-02-2020, 04:34 PM
Good questions Ironyak.
It’s not surprising there is a large number of similar blast results with high identity % ... this is something you would suspect for certain conserved sequences that are common among many viruses - or indeed many forms of life (an unrelated example: many organisms use heat shock proteins to aid in the proper folding of proteins and finding a heat shock protein in viruses, bacteria, snakes, humans, etc would not be uncommon). My point here being that the enormous number of matches is not surprising at all when blasting a short sequence.
A lot of times you don’t need to have a fully functional sequence that expresses a protein (think DNA > (transcribe) RNA > (translate) Amino Acid chain of protein) in order to have a functional or active site. I don’t know enough about the genes or open reading frames of 2019-nCov to be able to know for sure, but altering just a few amino acids of a functional protein like say a spike or glycoprotein of the capsids shell could be enough to alter the host range. The point here being that even such a tiny change could make a profound difference.
Another huge takeaway from Dr. Cottrell’s little talk is that the (Indian) paper focused on only four of the insertions - but there were many more. I’m more worried about the unknown than the known at this point - what other insertions have been made and in what genes ? (we know the replicase at least so far)
It’s not surprising there is a large number of similar blast results with high identity % ... this is something you would suspect for certain conserved sequences that are common among many viruses - or indeed many forms of life (an unrelated example: many organisms use heat shock proteins to aid in the proper folding of proteins and finding a heat shock protein in viruses, bacteria, snakes, humans, etc would not be uncommon). My point here being that the enormous number of matches is not surprising at all when blasting a short sequence.
A lot of times you don’t need to have a fully functional sequence that expresses a protein (think DNA > (transcribe) RNA > (translate) Amino Acid chain of protein) in order to have a functional or active site. I don’t know enough about the genes or open reading frames of 2019-nCov to be able to know for sure, but altering just a few amino acids of a functional protein like say a spike or glycoprotein of the capsids shell could be enough to alter the host range. The point here being that even such a tiny change could make a profound difference.
Another huge takeaway from Dr. Cottrell’s little talk is that the (Indian) paper focused on only four of the insertions - but there were many more. I’m more worried about the unknown than the known at this point - what other insertions have been made and in what genes ? (we know the replicase at least so far)