Structure of Ribosome-Inactivating Protein from Mirabilis jalapa and Its L12-Stalk-Dependent Inhibition of Escherichia coli Ribosome.
Nishida, N., Ninomiya, Y., Yoshida, T., Tanzawa, T., Maki, Y., Yoshida, H., Tsuge, H., Habuka, N.(2025) Toxins (Basel) 17
- PubMed: 41441611 
- DOI: https://doi.org/10.3390/toxins17120575
- Primary Citation of Related Structures:  
9X2O - PubMed Abstract: 
Mirabilis antiviral protein (MAP) is the type I ribosome-inactivating protein (RIP), which consists of an RNA N -glycosylase domain with no carbohydrate-binding domain. Unlike many RIPs, such as ricin or trichosanthin, which inactivate eukaryotic ribosomes, MAP also inactivates the E. coli ribosome by cleaving the N -glycosidic bond at A2660 of 23S ribosomal RNA. The structure of the wild-type MAP has not been revealed yet. Here, we expressed, purified, and crystallized the plural recombinant MAPs, including both E168Q and R171Q mutations (MAP-EQRQ) in E. coli , and determined the crystal structure of MAP-EQRQ at 2.1 Å resolution. According to the predicted structure with RNA (sarcin-ricin loop) and the mutant protein's activities using quantitative RT-PCR, we showed that residue R171 at the active site of MAP is a key residue to form the stable complex with target adenine. Furthermore, we showed that MAP bound the C-terminal domains of eukaryotic P2-stalk as well as E. coli L12-stalk.
- Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555, Japan.
Organizational Affiliation: 
















