1yrr
From Proteopedia
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Crystal Structure Of The N-Acetylglucosamine-6-Phosphate Deacetylase From Escherichia Coli K12 at 2.0 A Resolution
Overview
We report the crystal structure of the apoenzyme of, N-acetylglucosamine-6-phosphate (GlcNAc6P) deacetylase from Escherichia, coli (EcNAGPase) and the spectrometric evidence of the presence of Zn2+ in, the native protein. The GlcNAc6P deacetylase is an enzyme of the amino, sugar catabolic pathway that catalyzes the conversion of the GlcNAc6P into, glucosamine 6-phosphate (GlcN6P). The crystal structure was phased by the, single isomorphous replacement with anomalous scattering (SIRAS) method, using low-resolution (2.9 A) iodine anomalous scattering and it was, refined against a native dataset up to 2.0 A resolution. The structure is, similar to two other NAGPases whose structures are known from Thermotoga, maritima (TmNAGPase) and Bacillus subtilis (BsNAGPase); however, it shows, a phosphate ion bound at the metal-binding site. Compared to these, previous structures, the apoenzyme shows extensive conformational changes, in two loops adjacent to the active site. The E. coli enzyme is a tetramer, and its dimer-dimer interface was analyzed. The tetrameric structure was, confirmed in solution by small-angle X-ray scattering data. Although no, metal ions were detected in the present structure, experiments of, photon-induced X-ray emission (PIXE) spectra and of inductively coupled, plasma emission spectroscopy (ICP-AES) with enzyme that was neither, exposed to chelating agents nor metal ions during purification, revealed, the presence of 1.4 atoms of Zn per polypeptide chain. Enzyme inactivation, by metal-sequestering agents and subsequent reactivation by the addition, of several divalent cations, demonstrate the role of metal ions in, EcNAGPase structure and catalysis.
About this Structure
1YRR is a Single protein structure of sequence from Escherichia coli with PO4 and GOL as ligands. Active as N-acetylglucosamine-6-phosphate deacetylase, with EC number 3.5.1.25 Full crystallographic information is available from OCA.
Reference
Structural analysis of N-acetylglucosamine-6-phosphate deacetylase apoenzyme from Escherichia coli., Ferreira FM, Mendoza-Hernandez G, Castaneda-Bueno M, Aparicio R, Fischer H, Calcagno ML, Oliva G, J Mol Biol. 2006 Jun 2;359(2):308-21. Epub 2006 Mar 29. PMID:16630633
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