Function of aromatic amino acids in catalytic domain of nucleic acid enzyme

 Nucleic acid enzymes such as DNA/RNA polymerases usually possess several aromatic amino acids in their catalytic domain. These amino acids, phenylalanine, tyrosine, tryptophane and histidine consist of the aromatic ring in their side chain. The basic function of the aromatic amino acids in such catalytic domain is considered that they catch the nucleic acid by their aromatic ring during the enzymatic activity, resulting in the stabilization and positioning of reactive nucleic acids in optimal catalytic domain.