An Amsacta moorei entomopoxvirus ortholog of the poly(A) polymerase small subunit exhibits methyltransferase activity and is non-essential for virus growth.
Unlike the heterodimeric poly(A) polymerase (PAP) of vaccinia virus (VACV), the PAP from the Amsacta moorei entomopoxvirus, AMEV, is potentially derived from three subunits: a single large and two small subunits (AMV060 and AMV115). The VACV small subunit serves as a 2'-O-methyltransferase, a processivity factor for mRNA polyadenylation, and a transcription elongation factor. We wished to determine the structure-function relationships of the three putative AMEV PAP subunits. We show that AMV060 is expressed as an early gene persisting throughout infection, whereas AMV115 is expressed late. We demonstrate that AMV060 exhibits 2'-O-methyltransferase activity but the gene is not essential for virus growth. Absence of the AMV060 protein has no effect on the length of the poly(A) tails present in mRNA. No physical association was found between any of the putative AMEV PAP subunits. We therefore propose that mRNA polyadenylation does not require interactions between these three proteins.
Becker
Marie N
MN
Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32610, USA. mnbecker@ufl.edu
Todd
Tracie M
TM
Moyer
Richard W
RW
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D012321:DNA-Directed RNA Polymerases; D017996:Entomopoxvirinae / Q000502:physiology*; D005814:Genes, Viral; D007814:Larva / Q000821:virology; D008780:Methyltransferases / Q000378:metabolism*; D008969:Molecular Sequence Data; D009036:Moths / Q000821:virology; D011062:Polynucleotide Adenylyltransferase / Q000737:chemistry / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism*; D014779:Virus Replication
D021122:Protein Subunits; D014764:Viral Proteins; D008780:Methyltransferases; D011062:Polynucleotide Adenylyltransferase; D012321:DNA-Directed RNA Polymerases