TY - JOUR
T1 - RdRp or RT, That is the Question
AU - Peyambari, Mahtab
AU - Guan, Shengxi
AU - Roossinck, Marilyn J.
N1 - Publisher Copyright:
© 2021 The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
PY - 2021/11/1
Y1 - 2021/11/1
N2 - The RNA-dependent RNA polymerase (RdRp) of all known double-stranded RNA viruses is located within the viral particle and is responsible for the transcription and replication of the viral genome. Through an RT-PCR assay, we determined that purified virions, in vitro translated RdRp proteins, and purified recombinant RdRp proteins of partitiviruses also have reverse transcriptase (RT) function. We show that partitivirus RdRps 1) synthesized DNA from homologous and heterologous dsRNA templates; 2) are active using both ssRNA and dsRNA templates; and 3) are active at lower temperatures compared to an optimal reaction temperature of commercial RT enzymes. This finding poses an intriguing question: why do partitiviruses, with dsRNA genomes, have a polymerase with RT functions? In comparison, 3Dpol, the RdRp of poliovirus, did not show any RT activity. Our findings lead us to propose a new evolutionary model for RNA viruses where the RdRp of dsRNA viruses could be the ancestor of RdRps.
AB - The RNA-dependent RNA polymerase (RdRp) of all known double-stranded RNA viruses is located within the viral particle and is responsible for the transcription and replication of the viral genome. Through an RT-PCR assay, we determined that purified virions, in vitro translated RdRp proteins, and purified recombinant RdRp proteins of partitiviruses also have reverse transcriptase (RT) function. We show that partitivirus RdRps 1) synthesized DNA from homologous and heterologous dsRNA templates; 2) are active using both ssRNA and dsRNA templates; and 3) are active at lower temperatures compared to an optimal reaction temperature of commercial RT enzymes. This finding poses an intriguing question: why do partitiviruses, with dsRNA genomes, have a polymerase with RT functions? In comparison, 3Dpol, the RdRp of poliovirus, did not show any RT activity. Our findings lead us to propose a new evolutionary model for RNA viruses where the RdRp of dsRNA viruses could be the ancestor of RdRps.
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U2 - 10.1093/molbev/msab235
DO - 10.1093/molbev/msab235
M3 - Article
C2 - 34352104
AN - SCOPUS:85119599087
VL - 38
SP - 5082
EP - 5091
JO - Molecular Biology and Evolution
JF - Molecular Biology and Evolution
SN - 0737-4038
IS - 11
ER -