8QOK

Capra hircus reactive intermediate deaminase A mutant - E124A

Summary for 8QOK

• Entry DOI: 10.2210/pdb8qok/pdb
• Descriptor: 2-iminobutanoate/2-iminopropanoate deaminase (2 entities in total)
• Functional Keywords: enzyme, deaminase, unknown function
• Biological source: Capra hircus (goat)
• Total number of polymer chains: 2
• Total formula weight: 29067.20

Authors

Rizzi, G.,Visentin, C.,Ricagno, S. (deposition date: 2023-09-29, release date: 2024-06-26, Last modification date: 2025-01-15)

Primary citation

Rizzi, G.,Digiovanni, S.,Degani, G.,Barbiroli, A.,Di Pisa, F.,Popolo, L.,Visentin, C.,Vanoni, M.A.,Ricagno, S.
Site-directed mutagenesis reveals the interplay between stability, structure, and enzymatic activity in RidA from Capra hircus.
Protein Sci., 33:e5036-e5036, 2024

PubMed Abstract: Reactive intermediate deaminase A (RidA) is a highly conserved enzyme that catalyzes the hydrolysis of 2-imino acids to the corresponding 2-keto acids and ammonia. RidA thus prevents the accumulation of such potentially harmful compounds in the cell, as exemplified by its role in the degradation of 2-aminoacrylate, formed during the metabolism of cysteine and serine, catalyzing the conversion of its stable 2-iminopyruvate tautomer into pyruvate. Capra hircus (goat) RidA (RidA) was the first mammalian RidA to be isolated and described. It has the typical homotrimeric fold of the Rid superfamily, characterized by remarkably high thermal stability, with three active sites located at the interface between adjacent subunits. RidA exhibits a broad substrate specificity with a preference for 2-iminopyruvate and other 2-imino acids derived from amino acids with non-polar non-bulky side chains. Here we report a biophysical and biochemical characterization of eight RidA variants obtained by site-directed mutagenesis to gain insight into the role of specific residues in protein stability and catalytic activity. Each mutant was produced in Escherichia coli cells, purified and characterized in terms of quaternary structure, thermal stability and substrate specificity. The results are rationalized in the context of the high-resolution structures obtained by x-ray crystallography.

PubMed: 38801230
DOI: 10.1002/pro.5036

Experimental method

X-RAY DIFFRACTION (1.2 Å)