1) Amino acid 
Diphthamide is a modified histidine amino acid found in eukaryotic elongation factor 2 (eEF-2). It is usually found at position H715 in mammalian eEF2 (H699 in yeast). This residue is modified by the protein encoded by the DPH1 (OVCA1) gene. Dph1 knockout mice are inviable while heterozygotes develop diverse types of carcinomas and sarcomas. In hu...