1rnr

1rnr is a protein that functions as a ribosome inactivating protein (RIP). These proteins are characterized by their ability to irreversibly inhibit protein synthesis in eukaryotic cells by cleaving a specific adenine residue in the 28S rRNA of the large ribosomal subunit. This modification disrupts the ribosome's peptidyl transferase activity, effectively halting translation.

The 1rnr protein is typically found in plants, where it is believed to play a role in defense mechanisms. Its presence in seeds and other plant tissues can protect them from predation by insects and other herbivores that rely on protein synthesis for survival. While the exact biological function and distribution of 1rnr in all plant species are still areas of ongoing research, its classification as a type 2 RIP suggests a conserved mechanism of action.

Structurally, 1rnr is a single-chain protein belonging to the N-glycosidase family of enzymes. This structural classification is consistent with its enzymatic activity of cleaving glycosidic bonds within the rRNA. Studies on 1rnr and other RIPs have contributed to a broader understanding of protein synthesis regulation and have also explored their potential applications in areas such as antiviral and anticancer therapies due to their cytotoxic effects on target cells. Further investigation into the specific plant sources and ecological roles of 1rnr continues to be an active area of scientific inquiry.