Tyrosine-containing model peptides were oxidized by horseradish peroxidase (HRP). This led to a peptide polymerization via condensation of the aromatic rings. Dimers, trimers, and tetramers (depending on length position tyrosine in sequence) identified electron spray mass spectroscopy. The second-order rate constants second step HRP reduction (CII → E) was decreased presence positively charged amino group vicinity ring as determined stopped flow measurements [k3 = 19 398 M-1 s-1 k3 1016 for...

The virus protein linked to the genome (VPg) of plant potyviruses is a 25‐kDa covalently attached genomic RNA 5′ end. It was previously reported that VPg binds specifically eIF4E, mRNAcap‐binding eukaryotic translation initiation complex. We performed spectroscopic study interactions between lettuce eIF4E and from mosaic (LMV). cap analogue m 7 GDP bind at two distinct sites with similar affinity ( K d = 0.3 µ ). A deeper examination interaction pathway showed binding one ligand induces...

Elastin-based side-chain polymers (EBPs) were prepared by the polymerization of a methacrylate derivative pentapeptide valine−proline−glycine−valine−glycine (VPGVG) using reversible addition−fragmentation chain transfer (RAFT) polymerization. The polymerizations proceeded in controlled manner, yielding with narrow molecular weight distribution (polydispersity indices 1.03−1.23) and weights good agreement those predicted from initial monomer:initiator ratio for conversion obtained....

The eukaryotic translation initiation factor 4E (eIF4E) (the cap-binding protein) is involved in natural resistance against several potyviruses plants. In lettuce, the recessive genes mo1(1) and mo1(2) Lettuce mosaic virus (LMV) are alleles coding for forms of eIF4E unable, or less effective, to support accumulation. A recombinant LMV expressing a susceptible lettuce variety from its genome was able produce symptoms varieties. order identify amino acid residues necessary viral infection, we...

VPgs are viral proteins linked to the 5' end of some genomes. Interactions between several and eukaryotic translation initiation factors eIF4Es critical for plant infection. However, not restricted phytoviruses, being also involved in genome replication protein animal viruses. To date, structural data still limited small picornaviral VPgs. Recently three phytoviral were shown be natively unfolded proteins. In this paper, we report bacterial expression, purification biochemical...

Intrinsic disorder (ID) in proteins is defined as a lack of stable structure physiological conditions. Intrinsically disordered regions (IDRs) are highly abundant some RNA virus proteomes. Low topological constraints exerted on IDRs expected to buffer the effect numerous deleterious mutations and could be related remarkable adaptive potential viruses overcome resistance their host. To experimentally test this hypothesis natural pathosystem, set four variants Potato Y (PVY; Potyvirus genus)...

Reversible immobilization onto the surface of highly porous polymers through co-assembly stimuli-responsive is explored (see figure). Elastin-based side-chain (EBPs) are prepared by RAFT and attached to PEG-based emulsion-templated polymers, leading a responsive capable pH-controlled reversible immobilization.

In plants, the ubiquitin/26S proteasome system (UPS) plays a central role in protein degradation and is involved many steps of defence mechanisms, regardless types pathogen targeted. addition to its proteolytic activities, UPS ribonuclease (RNase) activity, previously detected 20S preparations from cauliflower sunflower (Helianthus annuus), has been shown specifically target plant viral RNAs vitro. this study, we show that recombinant Arabidopsis thaliana proteasomal α(5) subunit expressed...

The first proteome-wide analysis of intrinsic disorder in a major plant virus genus.

Potato virus A (PVA) is a single-stranded positive-sense RNA and member of the family Potyviridae. The PVA coat protein (CP) has an intrinsic capacity to self-assemble into filamentous virus-like particles, but mechanism responsible for initiation viral encapsidation in vivo remains unclear. Apart from virion assembly, CP also involved inhibition translation. In this study, we show that inhibits translation dose-dependent manner, through involving CP-encoding region. Analysis region,...

Binary mixtures of well-defined, stimuli-responsive elastin-based side-chain polymers show a single transition temperature that depends on blend composition.

The viral protein genome-linked (VPg) of potyviruses is a covalently linked to the 5' end RNA. It interacts with eIF4E, component cellular translation initiation complex. has been suggested that RNA-linked VPg could mimic mRNA cap, promoting synthesis proteins. Here, we report evidence for recruitment plant eIF4E by Lettuce mosaic virus (LMV, potyvirus) particles via VPg. Analysis population was performed enzyme-linked immunosorbent assay-based tests, either crude extracts LMV-infected...

Conformational intrinsic disorder is a feature present in many virus proteins. Intrinsically disordered regions (IDRs) have weaker structural requirement than ordered and mutations IDRs could lower impact on the fitness. This favor its exploration of adaptive solutions. The potyviral protein VPg contains with determinants for adaptation to host plant. To experimentally assess whether are more resistant regions, biologically relevant interaction between mutant libraries both eukaryotic...

Intrinsically disordered regions (IDRs) are abundant in the proteome of RNA viruses. The multifunctional properties these widely documented and their structural flexibility is associated with low constraint amino acid positions. Therefore, from an evolutionary stand point, could have a greater propensity to accumulate non-synonymous mutations (NS) than highly structured (ORs, or 'ordered regions'). To address this hypothesis, we compared distribution (NS), which relate here mutational...

A recommendation of: Guillaume Lafforgue, Marie Lefebvre, Thierry Michon, Santiago F. Elena How do plant RNA viruses overcome the negative effect of Muller s ratchet despite strong transmission bottlenecks? https://doi.org/10.1101/2023.08.01.550272

The infectious cycle of potyviruses requires the formation a complex between viral genome-linked protein VPg and host eukaryotic translation initiation factor 4E, eIF4E. Mutations associated with plant resistance to were previously mapped at eIF4E surface, while on virus side, mutations leading breaking identified within VPg. In present study, fluorescence spectroscopy was used probe contribution intrinsically disordered region bearing amino acids determinant breaking, VPg–eIF4E binding...

Protein intrinsic disorder is involved in many biological processes and good experimental models are valuable to investigate its functions. The potyvirus genome-linked protein, VPg, displays features of an intrinsically disordered protein. virus cycle requires the formation a complex between VPg eIF4E, one host translation initiation factors. An in-depth characterization hydrodynamic properties their binary VPg-eIF4E was carried out. Two complementary approaches, size-exclusion...

Muller's ratchet refers to the irreversible accumulation of deleterious mutations in small populations, resulting a decline overall fitness. This phenomenon has been extensively observed experiments involving microorganisms, including bacteriophages and yeast. While impact Muller’s on viruses largely studied animal RNA viruses, its effects plant remain poorly documented. Plant give rise large diverse populations that undergo significant bottlenecks during colonization distant tissues or...

ABSTRACT Muller’s ratchet refers to the irreversible accumulation of deleterious mutations in small populations, resulting a decline overall fitness. This phenomenon has been extensively observed experiments involving microorganisms, including bacteriophages and yeast. While impact on viruses largely studied animal RNA viruses, its effects plant remain poorly documented. Plant give rise large diverse populations that undergo significant bottlenecks during colonization distant tissues or...