User:Brian Hernandez/DOPA Decarboxylase
From Proteopedia
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==Introduction== | ==Introduction== | ||
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| - | <Structure load='1js6' size='500' frame='true' align='right' caption='DOPA Decarboxylase' scene='Insert optional scene name here' /> | ||
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DOPA decarboxylase (Aromatic L-Amino Acid Decarboxylase, tryptophan decarboxylase, 5-hydroxytryptophan decarboxylase, AAAD, or '''DDC''') is an essential [http://en.wikipedia.org/wiki/Lyase lyase] enzyme responsible for the conversion (via decarboxylation) of L-3,4-dihydroxyphenylalanine (L-DOPA) and L-5-hydroxytryptophan (5-HTP) to dopamine and serotonin. This 104 kDa protein is a tightly associated α<sub>2</sub>-dimer that belongs to the '''aspartate aminotransferase family''' (fold type 1) of PLP-dependent (vitamin B6-dependent) enzymes, and can be found in abundance in the nervous system, as well as the kidney. Because of its role in the biosynthesis of dopamine, DDC has been utilized in the treatment of [http://en.wikipedia.org/wiki/Parkinson's_disease Parksinon's disease]- a chronic, progressively neurological disorder, thought to be the result of degeneration of dopamine-producing cells in the '''substantia nigra pars compacta''' (brain structure in the mesencephalon that plays an important role in reward, addiction, and movement) of the brain. | DOPA decarboxylase (Aromatic L-Amino Acid Decarboxylase, tryptophan decarboxylase, 5-hydroxytryptophan decarboxylase, AAAD, or '''DDC''') is an essential [http://en.wikipedia.org/wiki/Lyase lyase] enzyme responsible for the conversion (via decarboxylation) of L-3,4-dihydroxyphenylalanine (L-DOPA) and L-5-hydroxytryptophan (5-HTP) to dopamine and serotonin. This 104 kDa protein is a tightly associated α<sub>2</sub>-dimer that belongs to the '''aspartate aminotransferase family''' (fold type 1) of PLP-dependent (vitamin B6-dependent) enzymes, and can be found in abundance in the nervous system, as well as the kidney. Because of its role in the biosynthesis of dopamine, DDC has been utilized in the treatment of [http://en.wikipedia.org/wiki/Parkinson's_disease Parksinon's disease]- a chronic, progressively neurological disorder, thought to be the result of degeneration of dopamine-producing cells in the '''substantia nigra pars compacta''' (brain structure in the mesencephalon that plays an important role in reward, addiction, and movement) of the brain. | ||
==Structure== | ==Structure== | ||
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| - | DDC consists of two monomers [SC], each with three distinct domains: the large domain [SC], the C-terminal small domain [SC], and the N-terminal domain [SC]. The large domain consists of the cofactor (PLP- pyridoxal phosphate) binding site and is comprised of a central, seven-stranded mixed β-sheet surrounded by eight α-helices [SC] in a typical α/β fold. The C-term. small domain consists of a four-stranded antiparallel β-sheet with three helices[SC] packed against the face opposite the large domain. The N-terminal domain (characteristic of all α-family enzymes) is composed of two parallel helices linked by an extended strand [SC]. This structure flaps over the top of the second subunit and vice versa, with the first helix of one subunit aligning parallel to the equivalent helix of the other subunit, thereby forming the extended dimer interface. Although it is unlikely that this domain represents an autonomous folding unit, it is most likely stable only in the context of the dimer by extending the interface between the two monomers. | + | DDC consists of two monomers [SC], each with three distinct domains: the large domain [SC], the C-terminal small domain [SC], and the N-terminal domain [SC]. The large domain consists of the cofactor (PLP- pyridoxal phosphate) binding site and is comprised of a central, seven-stranded mixed β-sheet surrounded by eight α-helices [SC] in a typical α/β fold. The C-term. small domain consists of a four-stranded antiparallel β-sheet with three helices[SC] packed against the face opposite the large domain. The N-terminal domain (characteristic of all α-family enzymes) is composed of two parallel helices linked by an extended strand [SC]. This structure flaps over the top of the second subunit and vice versa, with the first helix of one subunit aligning parallel to the equivalent helix of the other subunit, thereby forming the extended dimer interface. Although it is unlikely that this domain represents an autonomous folding unit, it is most likely stable only in the context of the dimer by extending the interface between the two monomers.</StructureSection> |
Revision as of 03:56, 27 November 2011
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