Reference : The DmpA aminopeptidase from Ochrobactrum anthropi LMG7991 is the prototype of a new ...
Scientific journals : Article
Life sciences : Biochemistry, biophysics & molecular biology
The DmpA aminopeptidase from Ochrobactrum anthropi LMG7991 is the prototype of a new terminal nucleophile hydrolase family.
Fanuel, L [> > > >]
Goffin, Colette mailto [Université de Liège - ULiège > > Centre d'ingénierie des protéines >]
Cheggour, A [> > > >]
Devreese, B [> > > >]
Van Driessche, G [> > > >]
Joris, Bernard mailto [Université de Liège - ULiège > Département des sciences de la vie > Physiologie et génétique bactériennes]
Van Beeumen, J [> > > >]
Frère, Jean-Marie mailto [Université de Liège - ULiège > > Centre d'ingénierie des protéines]
Biochemical Journal
Portland Press
Pt 1
Yes (verified by ORBi)
United Kingdom
[en] Amidohydrolases/classification/genetics/metabolism ; Amino Acid Sequence ; Aminopeptidases/classification/genetics/metabolism ; Bacterial Proteins ; Dipeptides/metabolism ; Enzyme Activation ; Gram-Negative Bacteria/enzymology ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Oligopeptides/metabolism ; Protein Precursors/classification/genetics/metabolism ; Recombinant Proteins ; Substrate Specificity
[en] The DmpA (d-aminopeptidase A) protein produced by Ochrobactrum anthropi hydrolyses p-nitroanilide derivatives of glycine and d-alanine more efficiently than that of l-alanine. When regular peptides are utilized as substrates, the enzyme behaves as an aminopeptidase with a preference for N-terminal residues in an l configuration, thus exemplifying an interesting case of stereospecificity reversal. The best-hydrolysed substrate is l-Ala-Gly-Gly, but tetra- and penta-peptides are also efficiently hydrolysed. The gene encodes a 375-residue precursor, but the active enzyme contains two polypeptides corresponding to residues 2-249 (alpha-subunit) and 250-375 (beta-subunit) of the precursor. Residues 249 and 250 are a Gly and a Ser respectively, and various substitutions performed by site-directed mutagenesis result in the production of an uncleaved and inactive protein. The N-terminal Ser residue of the beta-subunit is followed by a hydrophobic peptide, which is predicted to form a beta-strand structure. All these properties strongly suggest that DmpA is an N-terminal amidohydrolase. An exploration of the databases highlights the presence of a number of open reading frames encoding related proteins in various bacterial genomes. Thus DmpA is very probably the prototype of an original family of N-terminal hydrolases.

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