Structural highlights
Function
CAPSD_BPFR Capsid protein self-assembles to form an icosahedral capsid with a T=3 symmetry, about 26 nm in diameter, and consisting of 89 capsid proteins dimers (178 capsid proteins). Involved in viral genome encapsidation through the interaction between a capsid protein dimer and the multiple packaging signals present in the RNA genome. The capsid contains also 1 copy of the A2 maturation protein.[UniProtKB:P03612] Acts as a translational repressor of viral replicase synthesis late in infection. This latter function is the result of capsid protein interaction with an RNA hairpin which contains the replicase ribosome-binding site.[UniProtKB:P03612]
Publication Abstract from PubMed
The loop between beta-strands F and G in the coat protein of small RNA bacteriophages forms the interactions at the fivefold and threefold (quasi-sixfold) icosahedral axes. In many cases, mutations in this region renders the coat protein unable to form capsids. This FG loop has therefore been suggested to be of major importance for the virus assembly process by guiding the assembly and helping to define the correct curvature of the virus shell. We have determined the crystal structure of a phage fr capsid where the coat protein has a four-residue deletion in the FG loop. This mutant retains the ability to form virus capsids of normal size but has a significantly lower temperature stability than the wild type. The structure reveals that the mutated loops are flexible and too short to interact with each other. This seems incompatible with a role of the FG loop in the regulation of capsid size.
Structure of phage fr capsids with a deletion in the FG loop: implications for viral assembly.,Axblom C, Tars K, Fridborg K, Orna L, Bundule M, Liljas L Virology. 1998 Sep 15;249(1):80-8. PMID:9740779[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Axblom C, Tars K, Fridborg K, Orna L, Bundule M, Liljas L. Structure of phage fr capsids with a deletion in the FG loop: implications for viral assembly. Virology. 1998 Sep 15;249(1):80-8. PMID:9740779 doi:S0042-6822(98)99279-0
