X-ray sequence of luffaculin 1 and multiple sequence alignments. These alignments are of luffaculin 1 (LF1), luffin a (LUA), luffin b (LUB), α-momorcharin (MOM), trichosanthin (TCS) and bryodin (BRY). Highlighted residues are the active site residues. Panel Seq Ident indicates the sequence homology calculated by program clustalx 1.83. Panel CC_A and CC_B are the real space fit (RS fit, calculated by program O ranging from 0 to 1) of the residues between current luffaculin 1 and composite omit map of luffaculin 1. Panel Env represents the evaluation of chemical environment on residue pairs (Glu/Gln, Asp/Asn, Val/Thr) that cannot be distinguished by X-ray crystallography. H/L stands for high/low confidence in breaking down this ambiguity based on its chemical environment (hydrophobic interactions, hydrogen bonds and salt bridges).