title: Characterization of bacterial NMN deamidase as a Ser/Lys hydrolase expands diversity of serine amidohydrolases.
abstract: NMN deamidase (PncC) is a bacterial enzyme involved in NAD biosynthesis. We have previously demonstrated that PncC is structurally distinct from other known amidohydrolases. Here, we extended PncC characterization by mutating all potential catalytic residues and assessing their individual roles in catalysis through kinetic analyses. Inspection of these residues' spatial arrangement in the active site, allowed us to conclude that PncC is a serine-amidohydrolase, employing a Ser/Lys dyad for catalysis. Analysis of the PncC structure in complex with a modeled NMN substrate supported our conclusion, and enabled us to propose the catalytic mechanism.
authors: Department of Clinical Sciences, Polytechnic University of Marche, Ancona, Italy.
authors: Leonardo
authors: L
authors: Sorci
authors: Department of Agricultural, Food and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy.
authors: Lucia
authors: L
authors: Brunetti
authors: Department of Agricultural, Food and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy.
authors: Lucia
authors: L
authors: Cialabrini
authors: Department of Clinical Sciences, Polytechnic University of Marche, Ancona, Italy.
authors: Francesca
authors: F
authors: Mazzola
authors: A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia.
authors: Marat D
authors: MD
authors: Kazanov
authors: Laboratory for Molecular Sensing, IBP-CNR, Napoli, Italy.
authors: Sabato
authors: S
authors: D'Auria
authors: Department of Agricultural, Food and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy.
authors: Silverio
authors: S
authors: Ruggieri
authors: Department of Agricultural, Food and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy. Electronic address: n.raffaelli@univpm.it.
authors: Nadia
authors: N
authors: Raffaelli
mesh_terms: D000581:Amidohydrolases / Q000737:chemistry* / Q000235:genetics; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001051:Apoenzymes / Q000737:chemistry / Q000235:genetics; D020134:Catalytic Domain; D017124:Conserved Sequence; D004795:Enzyme Stability; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009537:Nicotinamide Mononucleotide / Q000737:chemistry; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid
chemical_list: D001051:Apoenzymes; D029968:Escherichia coli Proteins; D009537:Nicotinamide Mononucleotide; D000581:Amidohydrolases; C021861:nicotinamidenucleotide amidase
keywords: Amidohydrolase; Catalytic dyad; NMN deamidase; Pyridine nucleotide; Site-directed mutagenesis