The dapE-encoded N-Succinyl-l,l-Diaminopimelic Acid Desuccinylase from Haemophilus influenzae Is a Dinuclear Metallohydrolase

• Published in: Journal of the American Chemical Society Vol. 125; no. 48; pp. 14654 - 14655
• Main Authors: COSPER, Nathaniel J., BIENVENUE, David L., SHOKES, Jacob E., GILNER, Danuta M., TSUKAMOTO, Takashi, SCOTT, Robert A., HOLZ, Richard C.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 03-12-2003
• Subjects: Amidohydrolases - antagonists & inhibitors; Amidohydrolases - chemistry; Amidohydrolases - genetics; Amidohydrolases - metabolism; Biological and medical sciences; Crystalline structure; Enzyme Inhibitors - metabolism; Enzyme Inhibitors - pharmacology; Fourier Analysis; Fundamental and applied biological sciences. Psychology; Haemophilus influenzae - enzymology; Haemophilus influenzae - genetics; Molecular biophysics; Spectrometry, X-Ray Emission - methods; Structure in molecular biology; Pasteurellaceae; Molecular structure; Enzyme; Dinuclear complex; Bacteria; Hydrolases; Succinyl-diaminopimelate desuccinylase; Metalloenzyme; Zinc Complexes; Haemophilus influenzae; EXAFS spectrometry; Crystalline structure
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja036650v

The Zn K-edge extended X-ray absorption fine structure (EXAFS) spectra, of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) from Haemophilus influenzae have been recorded in the presence of one or two equivalents of Zn(II) (i.e. [Zn_(DapE)] and [ZnZn(DapE)]). The Fourier transforms of the Zn EXAFS are dominated by a peak at ca. 2.0 A, which can be fit for both [Zn_(DapE)] and [ZnZn(DapE)], assuming ca. 5 (N,O) scatterers at 1.96 and 1.98 A, respectively. A second-shell feature at ca. 3.34 A appears in the [ZnZn(DapE)] EXAFS spectrum but is significantly diminished in [Zn_(DapE)]. These data show that DapE contains a dinuclear Zn(II) active site. Since no X-ray crystallographic data are available for any DapE enzyme, these data provide the first glimpse at the active site of DapE enzymes. In addition, the EXAFS data for DapE incubated with two competitive inhibitors, 2-carboxyethylphosphonic acid and 5-mercaptopentanoic acid, are also presented.