Genomic features and evolutionary constraints in Saffold-like cardioviruses.
This study identified the complete genomic sequence of four type 2 and type 3 human Saffold-like cardioviruses (SLCVs) isolated in Germany and Brazil. The secondary structures of the SLCV internal ribosome entry sites (IRESs) were deduced based on RNA base-pairing conservation and co-variation, using an established Theiler's murine encephalomyelitis virus (TMEV) IRES structure as a reference. The SLCV IRES was highly similar to that of TMEV, but motifs critical in TMEV for binding of the polypyrimidine tract-binding protein (PTB) were disrupted. In TMEV, corresponding alterations have been associated with reduced neurovirulence in mice. In the non-structural genome region, there was evidence of multiple intertypic recombination events between different SLCV types. Between viruses of the same type, recombination also occurred in the capsid-encoding genome region. There were apparently no recombination events between mouse TMEV and human SLCV. In another genus of the family Picornaviridae, Enterovirus, natural recombination occurs strictly within species and can serve as an additional criterion for delimiting species. Accordingly, the results of this study suggest that SLCV and TMEV may represent distinct species within the genus Cardiovirus.
Research Laboratory for Infectious Diseases, Hospital Professor Edgar Santos, Federal University of Bahia, Salvador, Bahia, Brazil.
Jan Felix
JF
Drexler
Sigrid
S
Baumgarte
Luciano Kleber de Souza
LK
Luna
Andreas
A
Stöcker
Patrícia Silva
PS
Almeida
Tereza Cristina Medrado
TC
Ribeiro
Nadine
N
Petersen
Petra
P
Herzog
Célia
C
Pedroso
Carlos
C
Brites
Hugo da Costa
Hda C
Ribeiro
Anatoly
A
Gmyl
Christian
C
Drosten
Alexander
A
Lukashev
D000818:Animals; D001938:Brazil; D017943:Cardiovirus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D018188:Cardiovirus Infections / Q000821:virology; D019143:Evolution, Molecular; D016679:Genome, Viral; D005858:Germany; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000235:genetics*; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D017945:Theilovirus / Q000235:genetics; D017361:Viral Nonstructural Proteins / Q000235:genetics; D015678:Viral Structural Proteins / Q000235:genetics
D012367:RNA, Viral; D017361:Viral Nonstructural Proteins; D015678:Viral Structural Proteins