کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2189460 1096212 2006 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Crystal Structure of Nicotinic Acid Mononucleotide Adenylyltransferase from Staphyloccocus aureus: Structural Basis for NaAD Interaction in Functional Dimer
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Crystal Structure of Nicotinic Acid Mononucleotide Adenylyltransferase from Staphyloccocus aureus: Structural Basis for NaAD Interaction in Functional Dimer
چکیده انگلیسی

Bacterial nicotinic acid mononucleotide adenylyltransferase (NaMNAT; EC 2.7.7.18) encoded by the nadD gene, is essential for cell survival and is thus an attractive target for developing new antibacterial agents. The NaMNAT catalyzes the transfer of an adenylyl group of ATP to nicotinic acid mononucleotide (NaMN) to form nicotinic acid dinucleotide (NaAD). Two independently derived, high-resolution structures of Staphylococcus aureus NaMNAT–NaAD complexes establish the conserved features of the core dinucleotide-binding fold with other adenylyltransferases from bacteria to human despite a limited sequence conservation. The crystal structures reveal that the nicotinate carboxylates of NaAD are recognized by interaction with the main-chain amides of Thr85 and Tyr117, a positive helix dipole and two bridged-water molecules. Unlike other bacterial adenylyltransferases, where a partially conserved histidine residue interacts with the nicotinate ring, the Leu44 side-chain interacts with the nicotinate ring by van der Waals contact. Importantly, the S. aureus NaMNAT represents a distinct adenylyltransferase subfamily identifiable in part by common features of dimerization and substrate recognition in the loop connecting β5 to β6 (residues 132–146) and the additional β6 strand. The unique β6 strand helps orient the residues in the loop connecting β5 to β6 for substrate/product recognition and allows the β7 strand structural flexibility to make key dimer interface interactions. Taken together, these structural results provide a molecular basis for understanding the coupled activity and recognition specificity for S. aureus NaMNAT and for rational design of selective inhibitors.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Biology - Volume 360, Issue 4, 21 July 2006, Pages 814–825
نویسندگان
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