Tag Info: N-terminal 6xHis-sumostar-tagged. MW: 44.4 kDa. Function: The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. The B chain binds to cell receptors and probably facilitates the entry into the cell of the A chain; B chains are also responsible for cell agglutination (lectin activity). Inhibits growth of the human tumor cell line Molt4. Protein Families: Ribosome-inactivating protein family, Type 2 RIP subfamily.