Sequence of a cDNA clone encoding part of the small subunit of the ribulose-1,5-bisphosphate carboxylase of Nicotiana sylvestris

AbstractThe nucleotide sequence of the cDNA clone pSTV34 is reported. It codes for the 68 COOH-terminal amino acids of the protein coding for the small subunit of the ribulose bisphosphate carboxylase and has a 3′ non-translated region 195 base pairs long. In the coding region this clone is 72% homologous with the corresponding cDNA clone from Pisum sativum

Biologically active transcripts of alfalfa mosaic virus RNA3

AbstractTranscripts of the bicistronic RNA3 of alfalfa mosaic virus were synthesized using the in vitro T7 run-off transcription system. Synthetic RNA3 containing one additional G nucleotide at the 5' end were found to be infectious when coinoculated with RNA1 and RNA2 and coat protein

Protein 2A of Grapevine Fanleaf Nepovirus Is Implicated in RNA2 Replication and Colocalizes to the Replication Site

AbstractRNA2 of grapevine fanleaf virus is replicated in trans by the RNA1-encoded replication machinery. Full processing of the RNA2-encoded polyprotein P2 yields protein 2A of unknown function, the movement protein 2BMP, and the coat protein 2CCP. Analysis of a set of deletion mutants in the P2-coding sequence revealed that protein 2A is necessary but not sufficient for RNA2 replication. In addition to the 5′ and 3′ noncoding sequences and the 2A-coding sequence, an additional sequence coding for 2BMP and/or 2CCP or the green fluorescent protein (GFP) is necessary for RNA2 replication. When 2A fused to GFP (2AGFP) was transiently expressed in uninfected T-BY2 protoplasts, 2AGFP appeared as punctate structures evenly distributed in the cytoplasm. However, in cells cotransfected with grapevine fanleaf virus RNAs and the 2AGFP construct, 2AGFP was predominantly found in a juxtanuclear location along with 1Dpro and 1CVPg, two RNA1-encoded proteins involved in RNA replication. Viral RNA replication as traced by 5-bromouridine 5′ triphosphate (BrUTP) incorporation into newly synthesized RNA occurred at the same location. This colocalization is consistent with the hypothesis that 2A enables RNA2 replication through its association with the replication complex assembled from RNA1-encoded proteins

Involvement of RNA2-Encoded Proteins in the Specific Transmission of Grapevine Fanleaf Virus by Its Nematode Vector Xiphinema index

AbstractThe nepovirus Grapevine fanleaf virus (GFLV) is specifically transmitted by the nematode Xiphinema index. To identify the RNA2-encoded proteins involved in X. index-mediated spread of GFLV, chimeric RNA2 constructs were engineered by replacing the 2A, 2BMP, and/or 2CCP sequences of GFLV with their counterparts in Arabis mosaic virus (ArMV), a closely related nepovirus which is transmitted by Xiphinema diversicaudatum but not by X. index. Among the recombinant viruses obtained from transcripts of GFLV RNA1 and chimeric RNA2, only those which contained the 2CCP gene (504 aa) and 2BMP contiguous 9 C-terminal residues of GFLV were transmitted by X. index as efficiently as natural and synthetic wild-type GFLV, regardless of the origin of the 2A and 2BMP genes. As expected, ArMV was not transmitted probably because it is not retained by X. index. These results indicate that the determinants responsible for the specific spread of GFLV by X. index are located within the 513 C-terminal residues of the polyprotein encoded by RNA2