S. G. Siddell, P. J. Walker, E. J. Lefkowitz, A. R. Mushegian, M. J. Adams et al., Additional changes to taxonomy ratified in a special vote by the International Committee on Taxonomy of Viruses, Arch Virol, vol.164, pp.943-946, 2018.

Z. Song, Y. Xu, L. Bao, L. Zhang, P. Yu et al., From SARS to MERS, Thrusting Coronaviruses into the Spotlight. Viruses, p.11, 2019.

A. E. Gorbalenya, L. Enjuanes, J. Ziebuhr, and E. J. Snijder, Nidovirales: evolving the largest RNA virus genome, Virus Res, vol.117, pp.17-37, 2006.

E. J. Snijder, P. J. Bredenbeek, J. C. Dobbe, V. Thiel, J. Ziebuhr et al., Unique and conserved features of genome and proteome of SARS-coronavirus, an early split-off from the coronavirus group 2 lineage, J Mol Biol, vol.331, pp.991-1004, 2003.

A. Ramanathan, G. B. Robb, and S. Chan, mRNA capping: biological functions and applications, vol.44, pp.7511-7526, 2016.

E. Decroly, F. Ferron, J. Lescar, and B. Canard, Conventional and unconventional mechanisms for capping viral mRNA, Nat Rev Microbiol, vol.10, pp.51-65, 2011.

A. Van-vliet, S. L. Smits, P. Rottier, and R. J. De-groot, Discontinuous and nondiscontinuous subgenomic RNA transcription in a nidovirus, EMBO J, vol.21, pp.6571-6580, 2002.

M. M. Lai, C. D. Patton, and S. A. Stohlman, Further characterization of mRNA's of mouse hepatitis virus: presence of common 5'-end nucleotides, J Virol, vol.41, pp.557-565, 1982.

J. L. Sagripanti, R. O. Zandomeni, and R. Weinmann, The cap structure of simian hemorrhagic fever virion RNA, Virology, vol.151, pp.146-150, 1986.

E. Decroly, I. Imbert, B. Coutard, M. Bouvet, B. Selisko et al., Coronavirus nonstructural protein 16 is a cap-0 binding enzyme possessing (nucleoside-2'O)-methyltransferase activity, J Virol, vol.82, pp.8071-8084, 2008.

F. Ferron, L. Subissi, A. T. Silveira-de-morais, N. Le, M. Sevajol et al., Structural and molecular basis of mismatch correction and ribavirin excision from coronavirus RNA, Proc Natl Acad Sci U S A, vol.115, pp.162-171, 2018.
URL : https://hal.archives-ouvertes.fr/hal-02094607

Y. Ma, L. Wu, N. Shaw, Y. Gao, J. Wang et al., Structural basis and functional analysis of the SARS coronavirus nsp14-nsp10 complex, Proc Natl Acad Sci U S A, vol.112, pp.9436-9441, 2015.

Y. Chen, C. Su, M. Ke, J. X. Xu, L. Zhang et al., Biochemical and structural insights into the mechanisms of SARS coronavirus RNA ribose 2'-O-methylation by nsp16/nsp10 protein complex, Crystal structure and functional analysis of the SARS-coronavirus RNA cap, vol.7, p.1002059, 2011.

N. Perdigão, J. Heinrich, C. Stolte, K. S. Sabir, M. J. Buckley et al., Unexpected features of the dark proteome, Proc Natl Acad Sci, vol.112, pp.15898-15903, 2015.

C. Zeng, A. Wu, Y. Wang, S. Xu, Y. Tang et al., Identification and Characterization of a Ribose 2'-O-Methyltransferase Encoded by the Ronivirus Branch of Nidovirales, J Virol, vol.90, pp.6675-6685, 2016.

K. A. Ivanov and J. Ziebuhr, Human coronavirus 229E nonstructural protein 13: characterization of duplex-unwinding, nucleoside triphosphatase, and RNA 5'-triphosphatase activities, J Virol, vol.78, pp.7833-7838, 2004.

K. C. Lehmann, A. Gulyaeva, J. C. Zevenhoven-dobbe, G. Janssen, M. Ruben et al., Discovery of an essential nucleotidylating activity associated with a newly delineated conserved domain in the RNA polymerase-containing protein of all nidoviruses, Nucleic Acids Res, vol.43, pp.8416-8434, 2015.

E. Minskaia, T. Hertzig, A. E. Gorbalenya, V. Campanacci, C. Cambillau et al., Discovery of an RNA virus 3'->5' exoribonuclease that is critically involved in coronavirus RNA synthesis, Proc Natl Acad Sci, vol.103, pp.5108-5113, 2006.

M. Bouvet, I. Imbert, L. Subissi, L. Gluais, B. Canard et al., RNA 3'-end mismatch excision by the severe acute respiratory syndrome coronavirus nonstructural protein nsp10/nsp14 exoribonuclease complex, Proc Natl Acad Sci U S A, vol.109, pp.9372-9377, 2012.

C. Lauber, J. J. Goeman, C. Parquet-m-del, P. T. Nga, E. J. Snijder et al., The footprint of genome architecture in the largest genome expansion in RNA viruses, PLoS Pathog, vol.9, p.1003500, 2013.

L. D. Eckerle, X. Lu, S. M. Sperry, L. Choi, and M. R. Denison, High fidelity of murine hepatitis virus replication is decreased in nsp14 exoribonuclease mutants, J Virol, vol.81, pp.12135-12144, 2007.

K. Bukhari, G. Mulley, A. A. Gulyaeva, L. Zhao, G. Shu et al., Description and initial characterization of metatranscriptomic nidovirus-like genomes from the proposed new family Abyssoviridae, and from a sister group to the Coronavirinae, the proposed genus Alphaletovirus, Virology, vol.524, pp.160-171, 2018.

H. J. Debat, Expanding the size limit of RNA viruses: Evidence of a novel divergent nidovirus in California sea hare, with a ~35.9 kb virus genome, 2018.

H. J. Debat, An RNA Virome Associated to the Golden Orb-Weaver Spider Nephila clavipes. Front Microbiol, vol.8, 2017.

F. Armougom, S. Moretti, O. Poirot, S. Audic, P. Dumas et al., Expresso: automatic incorporation of structural information in multiple sequence alignments using 3D-Coffee, Nucleic Acids Res, vol.34, pp.604-608, 2006.

E. F. Pettersen, T. D. Goddard, C. C. Huang, G. S. Couch, D. M. Greenblatt et al., UCSF Chimera--a visualization system for exploratory research and analysis, J Comput Chem, vol.25, pp.1605-1612, 2004.

L. Zimmermann, A. Stephens, S. Nam, D. Rau, J. Kübler et al., A Completely Reimplemented MPI Bioinformatics Toolkit with a New HHpred Server at its Core, vol.430, pp.2237-2243, 2018.

M. Gouy, S. Guindon, and O. Gascuel, SeaView version 4: A multiplatform graphical user interface for sequence alignment and phylogenetic tree building, Mol Biol Evol, vol.27, pp.221-224, 2010.
URL : https://hal.archives-ouvertes.fr/lirmm-00511794

G. Yachdav, E. Kloppmann, L. Kajan, M. Hecht, T. Goldberg et al., PredictProtein--an open resource for online prediction of protein structural and functional features, Nucleic Acids Res, vol.42, pp.337-343, 2014.

P. Gouet, X. Robert, and E. Courcelle, ESPript/ENDscript: Extracting and rendering sequence and 3D information from atomic structures of proteins, Nucleic Acids Res, vol.31, pp.3320-3323, 2003.
URL : https://hal.archives-ouvertes.fr/hal-00314281

L. A. Kelley, S. Mezulis, C. M. Yates, M. N. Wass, M. Sternberg et al., The Phyre2 web portal for protein modeling, prediction and analysis, Nat Protoc, vol.10, pp.1188-1190, 2004.

J. L. Martin and F. M. Mcmillan, SAM (dependent) I AM: the S-adenosylmethioninedependent methyltransferase fold, Curr Opin Struct Biol, vol.12, pp.783-793, 2002.

M. Byszewska, M. ?mieta?ski, E. Purta, and J. M. Bujnicki, RNA methyltransferases involved in 5' cap biosynthesis, RNA Biol, vol.11, pp.1597-1607, 2014.

C. Fabrega, S. Hausmann, V. Shen, S. Shuman, and C. D. Lima, Structure and mechanism of mRNA cap (guanine-N7) methyltransferase, Mol Cell, vol.13, pp.77-89, 2004.

M. De-la-peña, O. Kyrieleis, and S. Cusack, Structural insights into the mechanism and evolution of the vaccinia virus mRNA cap N7 methyl-transferase, EMBO J, vol.26, pp.4913-4925, 2007.

G. Sutton, J. M. Grimes, D. I. Stuart, and P. Roy, Bluetongue virus VP4 is an RNA-capping assembly line, Nat Struct Mol Biol, vol.14, pp.449-451, 2007.

Y. Tao, D. L. Farsetta, M. L. Nibert, and S. C. Harrison, RNA synthesis in a cage--structural studies of reovirus polymerase lambda3, Cell, vol.111, pp.733-745, 2002.

D. Ray, A. Shah, M. Tilgner, Y. Guo, Y. Zhao et al., West Nile virus 5'-cap structure is formed by sequential guanine N-7 and ribose 2'-O methylations by nonstructural protein 5, J Virol, vol.80, pp.8362-8370, 2006.

N. K. Fox, S. E. Brenner, and J. Chandonia, SCOPe: Structural Classification of Proteins--extended, integrating SCOP and ASTRAL data and classification of new structures, Nucleic Acids Res, vol.42, pp.304-309, 2014.

T. Ahola and L. Kääriäinen, Reaction in alphavirus mRNA capping: formation of a covalent complex of nonstructural protein nsP1 with 7-methyl-GMP, Proc Natl Acad Sci, vol.92, pp.507-511, 1995.

M. Egloff, D. Benarroch, B. Selisko, J. Romette, and B. Canard, An RNA cap (nucleoside-2'-O-)-methyltransferase in the flavivirus RNA polymerase NS5: crystal structure and functional characterization, EMBO J, vol.21, pp.2757-2768, 2002.

G. C. Paesen, A. Collet, C. Sallamand, F. Debart, J. Vasseur et al., X-ray structure and activities of an essential Mononegavirales L-protein domain, Nat Commun, vol.6, p.8749, 2015.
URL : https://hal.archives-ouvertes.fr/hal-01439027

B. Martin, B. Coutard, T. Guez, G. C. Paesen, B. Canard et al., The methyltransferase domain of the Sudan ebolavirus L protein specifically targets internal adenosines of RNA substrates, in addition to the cap structure, Nucleic Acids Res, vol.46, pp.7902-7912, 2018.
URL : https://hal.archives-ouvertes.fr/hal-02094573

M. Ringeard, V. Marchand, E. Decroly, Y. Motorin, and Y. Bennasser, FTSJ3 is an RNA 2'-O-Methyltransferase recruited by HIV to avoid innate immunity sensing. Nature 2019, 47. Rana AK, Ankri S: Reviving the RNA World: An Insight into the Appearance of RNA Methyltransferases, Front Genet, vol.7, p.99, 2016.

D. Varshney, A. Petit, J. A. Bueren-calabuig, C. Jansen, D. A. Fletcher et al., Molecular basis of RNA guanine-7 methyltransferase (RNMT) activation by RAM, Nucleic Acids Res, vol.44, pp.960-967, 2000.

S. Hausmann, S. Zheng, C. Fabrega, S. W. Schneller, C. D. Lima et al., Encephalitozoon cuniculi mRNA cap (guanine N-7) methyltransferase: methyl acceptor specificity, inhibition BY S-adenosylmethionine analogs, and structure-guided mutational analysis, J Biol Chem, vol.280, pp.20404-20412, 2005.

O. Kyrieleis, J. Chang, M. De-la-peña, S. Shuman, and S. Cusack, Crystal structure of vaccinia virus mRNA capping enzyme provides insights into the mechanism and evolution of the capping apparatus, Struct Lond Engl, vol.22, pp.452-465, 1993.