The nucleotide sequence of potato virus A genomic RNA and its sequence similarities with other potyviruses

Abstract

The complete nucleotide sequence of potato virus A (PVA) was obtained from six independent cDNA clones. The RNA genome of PVA is 9565 nucleotides long and contains one open reading frame (ORF) of 9177 bases encoding a large polyprotein of 3059 amino acids with a calculated M r of 340K. Seven potential proteinase NIa, one HC-pro and one P1 proteinase recognition sites were found in PVA polyprotein by searching for cleavage site consensus sequences amongst the potyvirus group. The non-coding region preceding the ORF is 161 nucleotides long. The termination codon is followed by a 227-nucleotide sequence. Overall nucleotide sequence identity compared with several completely sequenced potyvirus genomes is between 53 and 58 %, with overall amino acid sequence identity between 65 and 71%. When the putative amino acid sequences of individual proteins of PVA were compared with the corresponding proteins of other potyviruses, P1 and P3 appeared the least conserved (34 to 53 %) whereas the other proteins were in most cases from 63 to 80 % identical to each other.

Potyvirus helper component-proteinase and coat protein (CP) have coordinated functions in virus-host interactions and the same CP motif affects virus transmission and accumulation.

“…The complete nucleotide and amino acid sequence of PVA-B11 has been published and numbering of nucleotides follows the previous study (Puurand et al, 1994). A full-length cDNA clone (icDNA) of PVA-B11 is available, from which infectious in vitro transcripts can be produced (Puurand et al, 1996).…”

“…The S7G substitution in CP (which reduced virus accumulation) restored transmissibility to PVA-B11 (no plants infected of the 40 plants inoculated), as shown by transmission of B11-DAG (11\20) and B11-U CP (5\10) to a rate similar to PVA-U (6\10). The motifs within HC-Pro required for aphidtransmissibility in other potyviruses (Atreya & Pirone, 1993 ;Huet et al, 1994) are conserved in PVA-B11 (Puurand et al, 1994 ;Rajama$ ki et al, 1998). The requirement of the CP Nterminal DAG motif for aphid-transmissibility has been proven in four other potyviruses by mutational analysis of the icDNA clones (Atreya et al, 1991 ;Gal-On et al, 1992 ;Flasinski et al, 1996 ;Lo!…”

Phosphorylation of the Potyvirus Capsid Protein by Protein Kinase CK2 and Its Relevance for Virus Infection [W]

“…PVA strain B11 (Puurand et al, 1994) was propagated in tobacco plants (Nicotiana tabacum cv SR1) as described previously (Ivanov et al, 2001). The GFP-tagged cDNA clone of PVA (35S-PVA-GFP NIb/CP ) was constructed according to the strategy proposed by Varrelmann and Maiss (2000).…”

Characterization of cocksfoot mottle sobemovirus genomic RNA and sequence comparison with related viruses

“…In general, no common sequence elements in plant viral VPgs have been found (Gorbalenya & Koonin, 1993). However, an amino acid triplet FDP is present in the VPg of the potyviruses tobacco etch virus (Allison et al, 1986;Murphy et al, 1991), potato Y virus (Robaglia et al, 1989) and potato A virus (Puurand et al, 1994). The significance of motif GxPxFDPxYG is unknown.…”