aminocarboxymuconate-semialdehyde decarboxylase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: 2-amino-3-carboxymuconate 6-semialdehyde + H+ = 2-aminomuconate 6-semialdehyde + CO2. [EC:4.1.1.45, RHEA:16557]

Aminocarboxymuconate-semialdehyde decarboxylase activity is a crucial step in the degradation pathway of aromatic compounds, particularly in the metabolism of the amino acid L-lysine and the aromatic compound benzoate. This enzymatic activity is catalyzed by the enzyme aminocarboxymuconate-semialdehyde decarboxylase (ACMSD), which is a pyridoxal phosphate-dependent decarboxylase.

The molecular function of ACMSD involves the removal of a carboxyl group (COO-) from aminocarboxymuconate-semialdehyde, a key intermediate in the pathway. This decarboxylation reaction is crucial for generating a molecule called 2-aminomuconate-semialdehyde, a crucial precursor in the further degradation of the aromatic compound.

The detailed molecular function of ACMSD can be summarized as follows:

1. **Substrate Binding:** ACMSD binds to the substrate, aminocarboxymuconate-semialdehyde, through interactions with its active site.
2. **Pyridoxal Phosphate (PLP) Cofactor:** The enzyme utilizes pyridoxal phosphate (PLP) as a cofactor. PLP forms a Schiff base with the ε-amino group of a lysine residue in the active site, creating a highly reactive intermediate.
3. **Decarboxylation:** The bound substrate undergoes a decarboxylation reaction, where the carboxyl group is removed and released as carbon dioxide (CO2). This reaction is facilitated by the PLP cofactor, which acts as a catalytic agent.
4. **Product Release:** The decarboxylated product, 2-aminomuconate-semialdehyde, is released from the enzyme, completing the catalytic cycle.

In summary, aminocarboxymuconate-semialdehyde decarboxylase activity is essential for the degradation of aromatic compounds. The enzyme catalyzes the removal of a carboxyl group from aminocarboxymuconate-semialdehyde, generating a precursor for further degradation in the pathway. This activity is crucial for maintaining cellular homeostasis and the proper functioning of metabolic processes.'
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Proteins (1)

Compounds (2)