Arenaviridae exoribonuclease presents genomic RNA edition capacity

Elsie Yekwa; Chutima Aphibanthammakit; Xavier Carnec; Bruno Coutard; Caroline Picard; Bruno Canard; Sylvain Baize; François Ferron

From the three subsets of sequences generated; i.e MAMV, LASV and MOPV; we observed that the three mutations S184L, S1021P and L1477S appeared in conserved regions in all three subsets, that none of the three mutants were reported in MOPV subset and finally that the three amino acid are subject to diverse selective pressure (Fig 7) . Indeed, serine at the position 184 represents the majority of the observed amino acid variants while the specific mutation S184L represents only 1 % of the total observed sequences in the LASV or MAMV subsets. This observation indicates that the mutation is viable but most likely costly to be maintained by the virus. On the other hand, at position 1021, the serine observed in MOPV subset does not represent the majority of the observed amino acid in the other subsets, the proline is by far the most frequent amino acids found (Fig 7) . In The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/541698 doi: bioRxiv preprint LASV, the serine subset represents only 3% of the observed amino acids at this position while 10% in the MAMV subset (Fig 7) . This observation indicates that this position in MOPV is an oddity compared to the others. It seems that the natural tendency in the L protein is to have a proline rather than a serine at this position. The fact that we observe that particular reversion in the NP-Exo(-) could indicate that for L MOPV there is a constraint at this particular position. Finally, at position 1477, the amino acid found at this position for the three subsets is a leucine (Fig 7) , indicating that, that particular position is under a high selective pressure. The mutation L1477S was never observed in any subsets, this mutation can be interpreted as unlikely and therefore considered as direct consequence of the NP-Exo(-).