Figure 1.
FIG. 1. Structures of the native and variant DHODAs. Top,
the native DHODA dimer and the residues chosen for mutations.
FMN (yellow) and orotate (orange) are shown as stick models. The
N- and C-terminals of the two subunits of the dimer are
indicated with an N and C, respectively. The catalytic active
base Cys-130 and the mutated residues are illustrated as stick
models and are color-coded according to their location in the
sequence. Blue: Arg-50, Pro-56, Arg-57, and the cis-proline loop
(42-58); pink: Ser-129, Cys-130, Pro-131, Lys-136, and the
active site loop (129-138); violet: Asn-127 and the -strand
123-127; green: Asn-67 and the loop 67-75; turquoise: Asn-193
and the loop 191-195; and red: Lys-213 and the Lys-213-helix
(211-214). Bottom, the A subunit of the native structure in the
presence of DTT and absence of orotate and three mutant
structures (K213E(Oro), P56A(Oro) and K136E) oriented as the
dimer at the top and color-coded according to the temperature
factors of the residues. The color code goes from blue to red
with blue representing residues with B-factors below or equal to
5 Å2 and red corresponding to B-factors above or equal to
55 Å2.
-strand
123-127; green: Asn-67 and the loop 67-75; turquoise: Asn-193
and the loop 191-195; and red: Lys-213 and the Lys-213-helix
(211-214). Bottom, the A subunit of the native structure in the
presence of DTT and absence of orotate and three mutant
structures (K213E(Oro), P56A(Oro) and K136E) oriented as the
dimer at the top and color-coded according to the temperature
factors of the residues. The color code goes from blue to red
with blue representing residues with B-factors below or equal to
5 Å2 and red corresponding to B-factors above or equal to
55 Å2.