Structural highlights
Function
[P21_BYVU] Acts as suppressor of RNA-mediated gene silencing, also known as post-transcriptional gene silencing (PTGS), a mechanism of plant viral defense that limits the accumulation of viral RNAs. Binds to ssRNAs and dsRNAs in vitro. Also functions as replication enhancer.[1]
Publication Abstract from PubMed
Many plant viruses encode proteins that suppress the antiviral RNA silencing response mounted by the host. The suppressors p19 from tombusvirus and p21 from Beet yellows virus appear to block silencing by directly binding siRNA, a critical mediator in the process. Here, we report the crystal structure of p21, which reveals an octameric ring architecture with a large central cavity of approximately 90 A diameter. The all alpha-helical p21 monomer consists of N- and C-terminal domains that associate with their neighboring counterparts through symmetric head-to-head and tail-to-tail interactions. A putative RNA binding surface is identified in the conserved, positive-charged inner surface of the ring. In contrast to the specific p19-siRNA duplex interaction, p21 is a general nucleic acid binding protein, interacting with 21 nt or longer single- and double-stranded RNAs in vitro. This study reveals an RNA binding structure adopted by the p21 silencing suppressor.
RNA silencing suppressor p21 of Beet yellows virus forms an RNA binding octameric ring structure.,Ye K, Patel DJ Structure. 2005 Sep;13(9):1375-84. PMID:16154094[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Reed JC, Kasschau KD, Prokhnevsky AI, Gopinath K, Pogue GP, Carrington JC, Dolja VV. Suppressor of RNA silencing encoded by Beet yellows virus. Virology. 2003 Feb 15;306(2):203-9. PMID:12642093
- ↑ Ye K, Patel DJ. RNA silencing suppressor p21 of Beet yellows virus forms an RNA binding octameric ring structure. Structure. 2005 Sep;13(9):1375-84. PMID:16154094 doi:http://dx.doi.org/S0969-2126(05)00278-9
