Crystal structures analysis
The crystal structure of human molybdopterin synthase complex (PDB ID: 5MPO, (Kopec, 2016) and molybdopterin synthase from Staphylococcus aureus complexed with precursor Z (PDB ID: 2QIE, (Daniels, 2008) were downloaded from the Protein Data Bank (Rose, 2017). Protein structures were aligned and analyzed using PyMol software [PyMol Schrödinger LLC]. The potential effects of substitutions at 158 and 159 positions in the molybdopterin synthase catalytic subunit were examined by the PredictSNP webserver (Bendl, 2014).