Establishing a reference array for the CS-αβ superfamily of defensive peptides

摘要: “Invertebrate defensins” belong to the cysteine-stabilized alpha-beta (CS-αβ), also known as scorpion toxin-like, superfamily. Some other peptides belonging this superfamily of defensive are indistinguishable from “defensins,” but have been assigned names, making it unclear what, if any, criteria must be met qualify an “invertebrate defensin.” In addition, there groups defensins in invertebrates and vertebrates that considered evolutionarily unrelated those CS-αβ This complicates analyses discussions peptide group. paper investigates for classifying a invertebrate defensin, suggests reference cysteine array may helpful discussing superfamily, proposes (rather than name “defensin”) is appropriate context studying evolution with fold. sequences were identified previous literature BLAST searches public databases. Sequences retrieved databases, relevant motifs used create conceptual alignment ten-cysteine array. Amino acid aligned MEGA6 manual adjustments ensure accurate cysteines. Phylogenetic performed (maximum likelihood) MrBayes (Bayesian). Across taxa, term “defensin” not consistently applied based on number cysteines, spacing pattern, spectrum antimicrobial activity, or phylogenetic relationship. The failed reveal any unify differentiate them various within can described by aligns their defining structural motifs. proposed addition current nomenclature compare clarify features relative one another. will facilitate analysis discussion evolutionary context, rather relying nomenclature.