0000000000133329
AUTHOR
Maija Bundule
The crystal structure of bacteriophage Qβ at 3.5 å resolution
Abstract Background: The capsid protein subunits of small RNA bacteriophages form a T=3 particle upon assembly and RNA encapsidation. Dimers of the capsid protein repress translation of the replicase gene product by binding to the ribosome binding site and this interaction is believed to initiate RNA encapsidation. We have determined the crystal structure of phage Qβ with the aim of clarifying which factors are the most important for particle assembly and RNA interaction in the small phages. Results The crystal structure of bacteriophage Qβ determined at 3.5 a resolution shows that the capsid is stabilized by disulfide bonds on each side of the flexible loops that are situated around the fi…
Crystal structure of bacteriophage fr capsids at 3.5 A resolution.
The structure of recombinant capsids of the bacterial virus fr has been determined by X-ray crystallography at 3.5 A resolution. The capsids were produced by expressing the fr coat protein in Escherichia coli, the natural host of the virus, and are probably essentially identical to the protein shell of the native virus. The structure was determined using molecular replacement with the protein shell of the related MS2 virus, and refined to a crystallographic R-factor of 0.228. A comparison of the protein shells of the viruses shows that they are very similar, and indicates that they may have a similar regulation of the assembly of the quasi-symmetrical protein shell.