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Length of encapsidated cargo impacts stability and structure of in vitro assembled alphavirus core-like particles
- Source :
- Journal of Physics
- Publication Year :
- 2017
- Publisher :
- IOP Publishing, 2017.
-
Abstract
- In vitro assembly of alphavirus nucleocapsid cores, called core-like particles (CLPs), requires a polyanionic cargo. There are no sequence or structure requirements to encapsidate single-stranded nucleic acid cargo. In this work, we wanted to determine how the length of the cargo impacts the stability and structure of the assembled CLPs. We hypothesized that cargo neutralizes the basic region of the alphavirus capsid protein and if the cargo is long enough, it will also act to scaffold the CP monomers together. Experimentally we found that CLPs encapsidating short 27mer oligonucleotides were less stable than CLPs encapsidating 48mer or 90mer oligonucleotides under different chemical and thermal conditions. Furthermore, cryo-EM studies showed there were structural differences between CLPs assembled with 27mer and 48mer cargo. To mimic the role of the cargo in CLP assembly we made a mutant (4D) where we substituted a cluster of four Lys residues in the CP with four Asp residues. We found that these few amino acid substitutions were enough to initiate CLP assembly in the absence of cargo. The cargo-free 4D CLPs show higher resistance to ionic strength and increased temperature compared to wild-type cargo containing CLPs suggesting their CLP assembly mechanism might also be different.
- Subjects :
- 0301 basic medicine
Paper
Mutant
Sequence (biology)
Alphavirus
macromolecular substances
Special Issue on Viral Capsids
environment and public health
03 medical and health sciences
General Materials Science
chemistry.chemical_classification
030102 biochemistry & molecular biology
biology
Chemistry
Oligonucleotide
self-assembly
Condensed Matter Physics
biology.organism_classification
In vitro
Amino acid
nucleic acid
virus capsid
Crystallography
030104 developmental biology
Capsid
Nucleic acid
Biophysics
protein
Subjects
Details
- Language :
- English
- ISSN :
- 1361648X and 09538984
- Volume :
- 29
- Issue :
- 48
- Database :
- OpenAIRE
- Journal :
- Journal of Physics
- Accession number :
- edsair.doi.dedup.....a71a9690289fd602cb834c9b71762f70