Virus assembly

Complex viruses Some virions are even more complex, being composed of several separate parts, with separate shapes and symmetries. The most complicated viruses in terms of structure are some of the bacterial viruses, which possess not only icosahedral heads but helical tails. In some bacterial viruses, such as the T4 virus of Escherichia coli, the tail itself is a complex structure. For instance, T4 has almost 20 separate proteins in the tail, and the T4 head has several more proteins. In such complex viruses, assembly is also complex. For instance, in T4 the complete tail is formed as a subassembly, and then the tail is added to the DNA-containing head. Finally, tail fibers formed from another protein are added to make the mature, infectious virus particle. 

Many aspects of DNA replication in filamentous phages are similar to that of < >X 174. The unique property, release without cell killing, can be briefly discussed. The release from the cell occurs by a budding process in which the virus particle is always released from the cell with the end containing the A protein first. Interestingly, the orientation of the virus particle across the cell membrane is the same for its entry and exit from the cell. There is no accumulation of intracellular virus particles the assembly of mature virus particles occurs on the inner cell membrane and virus assembly is coupled with the budding process. 

Wolf S, Maier I, Katsaros C, Muller DG. Virus assembly in Hincksia hincksiae (Ectocarpales, Phaeophyceae). An electron and fluorescence microscopic study. Protoplasma 1998 203 153-167. 

Aggregation and the Virus Assembly P. Jonathan, G. Butler, and Anthony C. H. Durham... 

Assembly of a virus Assembly of ribosomes Formation of micelles Assembly of the cell Surface metal coating... 

Self-organization systems under kinetic control (biological systems with genomic, enzymatic and/or evolutionary control), such as protein biosynthesis, virus assembly, formation of beehive and anthill, swarm intelligence. 

Kaplan AH, Zack JA, Knigge M, Paul DA, Kempf DJ, Norbeck DW, Swanstrom R. Partial inhibition of the human immunodeficiency virus type 1 protease results in aberrant virus assembly and the formation of noninfectious particles. J. Virol. 1993 67 4050-4055. 

Harrap KA (1972), The structure of nuclear polyhedrosis viruses. Ill Virus assembly, Virology 50 133-139. 

McPherson, A. "Micelle formation and crystallization as paradigms for virus assembly". Bioessays 27, 447- 58 (2005). 

The genome in influenza A and B types is enclosed within an outer lipoprotein envelope (Fig. 17.1). The Ml protein lines the inside of the envelope and is chemically bound to the ribonucleoprotein [14], The Ml protein plays an important role in the mediation of nuclear export of viral ribonucleoproteins and also in virus assembly and budding during the infectious cycle [5, 14, 15], An antigenic protein M2, which functions as a proton-selective ion channel, is present in the viral membrane of influenza A viruses [6, 13], In influenza B, the ion channel activity to aid virus uncoating in the endosome is carried out by the similar integral membrane protein BM2 [11],... 

The presence of pVIII in empty capsid confirms that the viral particle is at an early stage of virus assembly. Based on this finding and the uniqueness of pVIII to the empty capsid of the adenovirus, an assay was developed to quantify the empty capsid contaminants by measuring the amount of pVIII detected in SDS-PAGE during the recombinant adenovirus preparation [136]. 

Wengler, G., Boege, U., Wengler, G., Bischoff, H., and Wahn, K. (1982). The core protein of the alphavirus Sindbis virus assembles into core-like nucleoproteins with the viral genome RNA and with other single-stranded nucleic acids in vitro. Virology 118, 401-410. 

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