Structural analysis
There is no crystal structure of the protein carrying described
deletion; however, the analysis of the native conformation of the
molybdopterin synthase and comparison with the structure fromStaphylococcus aureus complexed with precursor Z shed light on
the consequences of the deletion. Human molybdopterin synthase complex
was crystallized as a dimer constituted of two heterodimers. Each
heterodimer consists of molybdopterin synthase sulfur carrier subunit
and molybdopterin synthase catalytic subunit. The Leu158 and Lys159
deletion occur in the catalytic subunit. The Leu158 and Lys159 residues
are located at the end of the last helix, close to the C-terminus of the
subunit, and together with the C-terminus, they participate in the
molybdopterin synthase sulfur carrier subunit binding (Figure 2A).
Moreover, the comparison of the structures of molybdopterin synthases
from human and Staphylococcus aureus suggests, that the Lys159
residue is essential for precursor Z binding (Figure 2B).
Figure 2