5vlz

Structural highlights

Function

[CAPSD_BPQBE] 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) (PubMed:27671640, PubMed:19913556). Involved in viral genome encapsidation through the interaction between a capsid protein dimer and the multiple packaging signals present in the RNA genome (PubMed:8943226, PubMed:27671640). Binding of the capsid proteins to the viral RNA induces a conformational change required for efficient T=3 shell formation (PubMed:19913556). The capsid contains also 1 copy of the A2 maturation protein (PubMed:27671640).^{[1] [2] [3]} 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.^[4] [MATA2_BPQBE] Induces host cell lysis (PubMed:11892805). Inhibits host MurA activity thereby blocking the synthesis of murein precursors necessary for the host cell wall biosynthesis (PubMed:11423662). May be responsible for the attachment to the host pilus. Makes extensive contacts with the viral genome (PubMed:28111107).^{[5] [6] [7] [8]}

References

1. ↑ Basnak G, Morton VL, Rolfsson O, Stonehouse NJ, Ashcroft AE, Stockley PG. Viral genomic single-stranded RNA directs the pathway toward a T=3 capsid. J Mol Biol. 2010 Feb 5;395(5):924-36. doi: 10.1016/j.jmb.2009.11.018. Epub 2009, Nov 12. PMID:19913556 doi:http://dx.doi.org/10.1016/j.jmb.2009.11.018
2. ↑ Gorzelnik KV, Cui Z, Reed CA, Jakana J, Young R, Zhang J. Asymmetric cryo-EM structure of the canonical Allolevivirus Qbeta reveals a single maturation protein and the genomic ssRNA in situ. Proc Natl Acad Sci U S A. 2016 Sep 26. pii: 201609482. PMID:27671640 doi:http://dx.doi.org/10.1073/pnas.1609482113
3. ↑ Lim F, Spingola M, Peabody DS. The RNA-binding site of bacteriophage Qbeta coat protein. J Biol Chem. 1996 Dec 13;271(50):31839-45. PMID:8943226
4. ↑ Lim F, Spingola M, Peabody DS. The RNA-binding site of bacteriophage Qbeta coat protein. J Biol Chem. 1996 Dec 13;271(50):31839-45. PMID:8943226
5. ↑ Bernhardt TG, Wang IN, Struck DK, Young R. A protein antibiotic in the phage Qbeta virion: diversity in lysis targets. Science. 2001 Jun 22;292(5525):2326-9. PMID:11423662 doi:http://dx.doi.org/10.1126/science.1058289
6. ↑ Karnik S, Billeter M. The lysis function of RNA bacteriophage Qbeta is mediated by the maturation (A2) protein. EMBO J. 1983;2(9):1521-6. PMID:11892805
7. ↑ Reed CA, Langlais C, Wang IN, Young R. A(2) expression and assembly regulates lysis in Qbeta infections. Microbiology. 2013 Mar;159(Pt 3):507-14. doi: 10.1099/mic.0.064790-0. Epub 2013, Jan 17. PMID:23329676 doi:http://dx.doi.org/10.1099/mic.0.064790-0
8. ↑ Rumnieks J, Tars K. Crystal Structure of the Maturation Protein from Bacteriophage Qbeta. J Mol Biol. 2017 Jan 19. pii: S0022-2836(17)30040-2. doi:, 10.1016/j.jmb.2017.01.012. PMID:28111107 doi:http://dx.doi.org/10.1016/j.jmb.2017.01.012