Sandbox Reserved 768: Difference between revisions
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present in several proteins, which functions in the dimerization and binding of amino acids. It is flexibly attached to the catalytic domain via a hinge region (Arg111–Thr117). <ref name= "flydal"/>. | present in several proteins, which functions in the dimerization and binding of amino acids. It is flexibly attached to the catalytic domain via a hinge region (Arg111–Thr117). <ref name= "flydal"/>. | ||
The catalytic domain contains the active site of the enzyme. It is composed of 13 α-helices and 8 β-strands <ref name= "fusetti"/> and houses the binding sites for the nonheme iron | The catalytic domain contains the active site of the enzyme. It is composed of 13 α-helices and 8 β-strands <ref name= "fusetti"/> and houses the binding sites for the nonheme iron atom, the cofactor, and substrate. The iron binds to two histidines (His285 and His290 in hPAH) and a glutamate (Glu330) in the deep cleft in the core of each monomer. <ref name=:"flydal"/>. | ||
The C-terminal oligomerization or tetramerization domain begins with an antiparallel-sheet | The C-terminal oligomerization or tetramerization domain begins with an antiparallel-sheet | ||
(residues 411–414, 421–424) | (residues 411–414, 421–424) | ||
and is formed by a C-terminal “arm” consisting of two β-strands, forming a β-ribbon, and a 40 Å long α-helix. This C-terminal arm extends over an adjacent monomer, thus bringing the four helices (one from each monomer) into a closely packed anti-parallel coiled-coil motif in the center of the structure (as can be seen in the tetramer structure above). <ref name= "fusetti"/>. The assembly of the enzyme occurs through a swapping mechanism in which the secondary structural elements mutually switch their position to promote oligomerization. <ref name="fusetti"/>. | and is formed by a C-terminal “arm” consisting of two β-strands, forming a β-ribbon, and a 40 Å long α-helix. This C-terminal arm extends over an adjacent monomer, thus bringing the four helices (one from each monomer) into a closely packed anti-parallel coiled-coil motif in the center of the structure (as can be seen in the tetramer structure above). <ref name= "fusetti"/>. The assembly of the enzyme occurs through a swapping mechanism in which the secondary structural elements mutually switch their position to promote oligomerization. <ref name="fusetti"/>. | ||
