1ee1

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spinqualitylabelsall models 1ee1, resolution 2.06Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF NH3-DEPENDENT NAD+ SYNTHETASE FROM BACILLUS SUBTILIS COMPLEXED WITH ONE MOLECULE ATP, TWO MOLECULES DEAMIDO-NAD+ AND ONE MG2+ ION

Overview

The NH(3)-dependent NAD(+) synthetase (NADS) participates in the, biosynthesis of nicotinamide adenine dinucleotide (NAD(+)) by transforming, nicotinic acid adenine dinucleotide (NaAD) to NAD(+). The structural, behavior of the active site, including stabilization of flexible loops, 82-87 and 204-225, has been studied by determination of the crystal, structures of complexes of NADS with natural substrates and a substrate, analog. Both loops are stabilized independently of NaAD and solely from, the ATP-binding site. Analysis of the binding contacts suggests that the, minor loop 82-87 is stabilized primarily by a hydrogen bond with the, adenine base of ATP. Formation of a coordination complex with Mg(2+) in, the ATP-binding site may contribute to the stabilization of the major loop, 204-225. The major loop has a role in substrate recognition and, stabilization, in addition to the protection of the reaction intermediate, described previously. A second and novel Mg(2+) position has been observed, closer to the NaAD-binding site in the structure crystallized at pH 7.5, where the enzyme is active. This could therefore be the catalytically, active Mg(2+).

About this Structure

1EE1 is a Single protein structure of sequence from Bacillus subtilis with MG, DND and ATP as ligands. Active as NAD(+) synthase (glutamine-hydrolyzing), with EC number 6.3.5.1 Full crystallographic information is available from OCA.

Reference

Stabilization of active-site loops in NH3-dependent NAD+ synthetase from Bacillus subtilis., Devedjiev Y, Symersky J, Singh R, Jedrzejas M, Brouillette C, Brouillette W, Muccio D, Chattopadhyay D, DeLucas L, Acta Crystallogr D Biol Crystallogr. 2001 Jun;57(Pt 6):806-12. Epub 2001, May 25. PMID:11375500

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