Several residues such as MET75 or MET136 ranked very high by b-centrality can be found in the midfield of the PCVA ranking at rank 79 and 81, respectively. Additionally, their low scores in CSA and FSA (MET136 is not considered in CSA) indicate a small electrostatic effect. Nevertheless, both methionine side chains are positioned towards the active site and especially MET75 is proximal to SER71, which was considered to have an important effect on SAM . Since the network analysis approach aims at identifying additional residues which do not primarily apply a high electrostatic effect, but are crucial in allosteric interactions, we assume these amino acids to be interesting to be included in the QM region.