1ih8: Difference between revisions
New page: left|200px<br /><applet load="1ih8" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ih8, resolution 1.90Å" /> '''NH3-dependent NAD+ S... |
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[[Image:1ih8.gif|left|200px]]<br /><applet load="1ih8" size=" | [[Image:1ih8.gif|left|200px]]<br /><applet load="1ih8" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1ih8, resolution 1.90Å" /> | caption="1ih8, resolution 1.90Å" /> | ||
'''NH3-dependent NAD+ Synthetase from Bacillus subtilis Complexed with AMP-CPP and Mg2+ ions.'''<br /> | '''NH3-dependent NAD+ Synthetase from Bacillus subtilis Complexed with AMP-CPP and Mg2+ ions.'''<br /> | ||
==Overview== | ==Overview== | ||
The NH(3)-dependent NAD(+) synthetase (NADS) participates in the | 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== | ==About this Structure== | ||
1IH8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis] with MG and APC as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/NAD(+)_synthase_(glutamine-hydrolyzing) NAD(+) synthase (glutamine-hydrolyzing)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.5.1 6.3.5.1] Full crystallographic information is available from [http:// | 1IH8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=APC:'>APC</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/NAD(+)_synthase_(glutamine-hydrolyzing) NAD(+) synthase (glutamine-hydrolyzing)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.5.1 6.3.5.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IH8 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: ligase]] | [[Category: ligase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:11:48 2008'' | ||
Revision as of 14:11, 21 February 2008
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NH3-dependent NAD+ Synthetase from Bacillus subtilis Complexed with AMP-CPP and Mg2+ ions.
OverviewOverview
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 StructureAbout this Structure
1IH8 is a Single protein structure of sequence from Bacillus subtilis with and as ligands. Active as NAD(+) synthase (glutamine-hydrolyzing), with EC number 6.3.5.1 Full crystallographic information is available from OCA.
ReferenceReference
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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