8qop | pdb_00008qop
Capra hircus reactive intermediate deaminase A - K78A
Structural highlights
FunctionRIDA_CAPHI Catalyzes the hydrolytic deamination of enamine/imine intermediates that form during the course of normal metabolism. May facilitate the release of ammonia from these potentially toxic reactive metabolites, reducing their impact on cellular components. It may act on enamine/imine intermediates formed by several types of pyridoxal-5'-phosphate-dependent dehydratases including L-threonine dehydratase.[UniProtKB:P52758] Also promotes endoribonucleolytic cleavage of some transcripts by promoting recruitment of the ribonuclease P/MRP complex. Acts by bridging YTHDF2 and the ribonuclease P/MRP complex. RIDA/HRSP12 binds to N6-methyladenosine (m6A)-containing mRNAs containing a 5'-GGUUC-3' motif: cooperative binding of RIDA/HRSP12 and YTHDF2 to such transcripts lead to recruitment of the ribonuclease P/MRP complex and subsequent endoribonucleolytic cleavage.[UniProtKB:P52758] Publication Abstract from PubMedReactive 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 ((Ch)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. (Ch)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 (Ch)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. Site-directed mutagenesis reveals the interplay between stability, structure, and enzymatic activity in RidA from Capra hircus.,Rizzi G, Digiovanni S, Degani G, Barbiroli A, Di Pisa F, Popolo L, Visentin C, Vanoni MA, Ricagno S Protein Sci. 2024 Jun;33(6):e5036. doi: 10.1002/pro.5036. PMID:38801230[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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