9r7u
RNA-free helical (h8.5) virus-like particle composed of PVA (isolate B11) coat protein
Structural highlights
FunctionPOLG_PVMA Required for aphid transmission and also has proteolytic activity. Only cleaves a Gly-Gly dipeptide at its own C-terminus. Interacts with virions and aphid stylets. Acts as a suppressor of RNA-mediated gene silencing, also known as post-transcriptional gene silencing (PTGS), a mechanism of plant viral defense that limits the accumulation of viral RNAs. May have RNA-binding activity.[UniProtKB:P04517] Has helicase activity. It may be involved in replication. Indispensable for virus replication (By similarity). Reduces the abundance of host transcripts related to jasmonic acid biosynthesis therefore altering the host defenses (By similarity). In order to increase its own stability, decreases host protein degradation pathways (By similarity).[UniProtKB:P13529][UniProtKB:P89509] Indispensable for virus replication.[UniProtKB:P09814] Mediates the cap-independent, EIF4E-dependent translation of viral genomic RNAs (By similarity). Binds to the cap-binding site of host EIF4E and thus interferes with the host EIF4E-dependent mRNA export and translation (By similarity). VPg-RNA directly binds EIF4E and is a template for transcription (By similarity). Also forms trimeric complexes with EIF4E-EIF4G, which are templates for translation (By similarity).[UniProtKB:P18247] Has RNA-binding and proteolytic activities.[UniProtKB:P04517] An RNA-dependent RNA polymerase that plays an essential role in the virus replication. Involved in aphid transmission, cell-to-cell and systemis movement, encapsidation of the viral RNA and in the regulation of viral RNA amplification.[UniProtKB:P04517] Publication Abstract from PubMedPotyviruses are the largest group of plant positive-sense single-stranded RNA viruses and represent a major economic burden worldwide. Their coat protein (CP) forms a filamentous, flexible capsid around the genomic RNA. However, information is still lacking on the mechanisms of virion assembly, disassembly and stability, which is central to understanding virus biology and control. Here, we investigate the role of CP in these processes using structural, biochemical and biophysical studies of five potyviral CPs from three phylogenetic clades combined with bioinformatics and in planta experiments. Our results suggest that, while potyviruses have a conserved virion structure, the amino acids forming the CP-CP and CP-RNA interactions leading to this structure are species-specific. We show that the species-specific CP sequence also determines the architecture of RNA-free virus-like particles (VLPs) and the degree of their structural polymorphism. We identify the residues that determine this specificity at distinct S1-S4 interaction sites. In contrast, a highly conserved charged amino acid triad at the CP-CP interface is essential for the stability of virions and RNA-free VLPs. These results contribute to understanding the molecular mechanism of potyviral virion assembly and highlight the significance of the amino acid sequence of selected CPs in potential biotechnological or biomedical applications. Species-specific structural adaptation of the potyviral coat protein in virions and virus-like particles.,Koritnik N, Kezar A, Kavcic L, Znidaric MT, Leonardi A, De S, Pollari M, Makinen K, Podobnik M Commun Biol. 2026 Jan 13. doi: 10.1038/s42003-025-09502-w. PMID:41530503[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||
