1b65

Structure of l-aminopeptidase d-ala-esterase/amidase from ochrobactrum anthropi, a prototype for the serine aminopeptidases, reveals a new variant among the ntn hydrolase fold

spinqualitylabelsall models 1b65, resolution 1.82Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1b65 is a 6 chain structure with sequence from Brucella anthropi. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.82Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q59632_BRUAN Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Background: The L-aminopeptidase D-Ala-esterase/amidase from Ochrobactrum anthropi (DmpA) releases the N-terminal L and/or D-Ala residues from peptide substrates. This is the only known enzyme to liberate N-terminal amino acids with both D and L stereospecificity. The DmpA active form is an alphabeta heterodimer, which results from a putative autocatalytic cleavage of an inactive precursor polypeptide. Results: The crystal structure of the enzyme has been determined to 1.82 A resolution using the multiple isomorphous replacement method. The heterodimer folds into a single domain organised as an alphabetabetaalpha sandwich in which two mixed beta sheets are flanked on both sides by two alpha helices. Conclusions: DmpA shows no similarity to other known aminopeptidases in either fold or catalytic mechanism, and thus represents the first example of a novel family of aminopeptidases. The protein fold of DmpA does, however, show structural homology to members of the N-terminal nucleophile (Ntn) hydrolase superfamily. DmpA presents functionally equivalent residues in the catalytic centre when compared with other Ntn hydrolases, and is therefore likely to use the same catalytic mechanism. In spite of this homology, the direction and connectivity of the secondary structure elements differ significantly from the consensus Ntn hydrolase topology. The DmpA structure thus characterises a new subfamily, but supports the common catalytic mechanism for these enzymes suggesting an evolutionary relationship. A new variant of the Ntn hydrolase fold revealed by the crystal structure of L-aminopeptidase D-ala-esterase/amidase from Ochrobactrum anthropi.,Bompard-Gilles C, Villeret V, Davies GJ, Fanuel L, Joris B, Frere JM, Van Beeumen J Structure. 2000 Feb 15;8(2):153-62. PMID:10673442 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aminopeptidase 3D structures

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