1f9a

CRYSTAL STRUCTURE ANALYSIS OF NMN ADENYLYLTRANSFERASE FROM METHANOCOCCUS JANNASCHII

spinqualitylabelsall models 1f9a, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1f9a is a 6 chain structure with sequence from Atcc 43067. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ATP, MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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: Nicotinamide adenine dinucleotide (NAD(+)) is an essential cofactor involved in fundamental processes in cell metabolism. The enzyme nicotinamide mononucleotide adenylyltransferase (NMN AT) plays a key role in NAD(+) biosynthesis, catalysing the condensation of nicotinamide mononucleotide and ATP, and yielding NAD(+) and pyrophosphate. Given its vital role in cell life, the enzyme represents a possible target for the development of new antibacterial agents. RESULTS: The structure of NMN AT from Methanococcus jannaschii in complex with ATP has been solved by X-ray crystallography at 2.0 A resolution, using a combination of single isomorphous replacement and density modification techniques. The structure reveals a hexamer with 32 point group symmetry composed of alpha/beta topology subunits. The catalytic site is located in a deep cleft on the surface of each subunit, where one ATP molecule and one Mg(2+) are observed. A strictly conserved HXGH motif (in single-letter amino acid code) is involved in ATP binding and recognition. CONCLUSIONS: The structure of NMN AT closely resembles that of phosphopantetheine adenylyltransferase. Remarkably, in spite of the fact that the two enzymes share the same fold and hexameric assembly, a striking difference in their quaternary structure is observed. Moreover, on the basis of structural similarity including the HXGH motif, we identify NMN AT as a novel member of the newly proposed superfamily of nucleotidyltransferase alpha/beta phosphodiesterases. Our structural data suggest that the catalytic mechanism does not rely on the direct involvement of any protein residues and is likely to be carried out through optimal positioning of substrates and transition-state stabilisation, as is proposed for other members of the nucleotidyltransferase alpha/beta phosphodiesterase superfamily. Structure of nicotinamide mononucleotide adenylyltransferase: a key enzyme in NAD(+) biosynthesis.,D'Angelo I, Raffaelli N, Dabusti V, Lorenzi T, Magni G, Rizzi M Structure. 2000 Sep 15;8(9):993-1004. PMID:10986466 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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