Abstract
Ribosome-inactivating proteins (RIP) are RNA N-glycosidases that inactivate ribosomes by specifically depurinating a conserved adenine residue at the α-sarcin/ricin loop of 28S rRNA. Recent studies have pointed to the involvement of the C-terminal domain of the eukaryotic stalk proteins in facilitating the toxic action of RIPs. This review highlights how structural studies of eukaryotic stalk proteins provide insights into the recruitment of RIPs to the ribosomes. Since the C-terminal domain of eukaryotic stalk proteins is involved in specific recognition of elongation factors and some eukaryote-specific RIPs (e.g., trichosanthin and ricin), we postulate that these RIPs may have evolved to hijack the translation-factor-recruiting function of ribosomal stalk in reaching their target site of rRNA.
Highlights
Ribosome inactivating protein (RIP) belongs to a family of proteins that inactivate ribosomes.Most Ribosome-inactivating proteins (RIP) discovered were isolated from plants, but a few RIPs were found in bacteria (e.g., Shiga and shiga-like toxins) [1].All RIPs contain an RNA N-glycosidase catalytic domain that enzymatically removes a specific adenine base from the 28S rRNA
Most RIPs discovered were isolated from plants, but a few RIPs were found in bacteria (e.g., Shiga and shiga-like toxins) [1]
On the other hand, shortening or truncation of the flexible linker resulted in ribosomes insensitive to the action of TCS [27]. These results suggest that both the C-terminal domain (CTD) and flexible linker of eukaryotic stalk proteins are responsible for recruiting these RIPs to the sarcin/ricin loop (SRL) where the toxin can carry out its N-glycosidase activity
Summary
Ribosome inactivating protein (RIP) belongs to a family of proteins that inactivate ribosomes.Most RIPs discovered were isolated from plants (e.g., ricin, trichosanthin, maize RIP, pokeweed antiviral proteins), but a few RIPs were found in bacteria (e.g., Shiga and shiga-like toxins) [1].All RIPs contain an RNA N-glycosidase catalytic domain that enzymatically removes a specific adenine base from the 28S rRNA. It has been shown that the CTD of stalk proteins P1/P2 and L12 are responsible for domain-specific binding of elongation factors [8,9]. L10 with CTD of P0, and showed that the resulting chimeric stalk protein was able to bind two copies of P1/P2 heterodimers and enabled the reconstituted hybrid ribosomes to use eukaryotic elongation factors.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
