Irreversibly relaxes supercoiled DNA and catalyzes double-stranded breakage. Acts also as a ribosome inactivating protein. Endohydrolysis of the N-glycosidic bond at one specific adenosine on the 28S rRNA. Bound to a branched hexasaccharide. Possesses anti-HIV and antitumoral activities. Inhibits HIV-1 integrase. Manganese or zinc required for enhancing substrate binding rather than catalysis. The oligosaccharide does not influence the fold of the polypeptide chain and probably does not play a role in the enzymatic function. Is not toxic to uninfected normal cells as it cannot enter into them. Belongs to the ribosome-inactivating protein family. Type 1 RIP subfamily.