I have been looking into the 4 unique mutations (all T->C) mentioned by @evogytis in EBOV_2014_G5119.1. These mutations are all found in the GP gene, so they might be of interest. Two of these mutations (positions 6675 and 6677) are in Y213, causing a Y->H amino acid change. The mutation at position 6678 also causes a Y->H change, this time in Y214. The fourth mutation is synonymous, at residue G224.
The non-synonymous mutations at Y213 and Y214 might be interesting because residues 190-213 are thought to be the site of endosomal cathepsin cleavage, which removes the mucin-like region of GP, perhaps exposing the receptor-binding region during viral infection (see paper). Does anyone have other thoughts on this region? @alin
Two other observations:
- the synonymous mutation at position 6710 was also seen in three sequences from the 1994/1995 outbreak. This suggests to me that it's probably not just an error, since the mutations have been seen before
- position 6677 is a T in all 2014 sequences (except G5119.1), but a C in all previously published sequences. Is this a back-mutation to the sequence before 2014?