2e5b: Difference between revisions
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[[Image: | ==Crystal structure of Human NMPRTase as free-form== | ||
<StructureSection load='2e5b' size='340' side='right' caption='[[2e5b]], [[Resolution|resolution]] 2.00Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2e5b]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2E5B OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2E5B FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2e5c|2e5c]], [[2e5d|2e5d]]</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Nicotinamide_phosphoribosyltransferase Nicotinamide phosphoribosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.2.12 2.4.2.12] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2e5b FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2e5b OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2e5b RCSB], [http://www.ebi.ac.uk/pdbsum/2e5b PDBsum]</span></td></tr> | |||
<table> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/e5/2e5b_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Nicotinamide (NM) phosphoribosyltransferase (NMPRTase) catalyzes the reaction of NM and 5'-phosphoribosyl-1'-pyrophosphate (PRPP) to form NM mononucleotide (NMN) and pyrophosphate (PPi) in the pathway of NAD-biosynthesis. Monitoring the (1)H and (31)P NMR spectra of the reaction mixture, we found that this reaction is reversible as dictated by the equilibrium constant K = [NMN][PPi]/([NM][PRPP]) = 0.14, which agreed well with the ratio of second-order rate constants for forward and backward reactions, K = 0.16. The crystal structures of this enzyme in the free form and bound to NM and PRPP at the resolution of 2.0-2.2 A were essentially identical to that of the complex with NMN, except for some variations that could facilitate the substitution reaction by fixing the nucleophile and the leaving group for the requisite inversion of configuration at the C1' carbon of the ribose ring. In the active site near the C1' atom of the bound PRPP or NMN, there was neither negatively charged group nor waterproof environment necessary to support the feasibility of a ribo-oxocarbocation intermediate inherent in the S(N)1 mechanism. The structures and catalytic mechanism thus revealed are also discussed in connection with the multiple biological functions of NMPRTase. | |||
Structure and reaction mechanism of human nicotinamide phosphoribosyltransferase.,Takahashi R, Nakamura S, Nakazawa T, Minoura K, Yoshida T, Nishi Y, Kobayashi Y, Ohkubo T J Biochem. 2010 Jan;147(1):95-107. Epub 2009 Oct 9. PMID:19819904<ref>PMID:19819904</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Phosphoribosyltransferase|Phosphoribosyltransferase]] | *[[Phosphoribosyltransferase|Phosphoribosyltransferase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Nicotinamide phosphoribosyltransferase]] | [[Category: Nicotinamide phosphoribosyltransferase]] | ||
Revision as of 05:52, 30 September 2014
Crystal structure of Human NMPRTase as free-formCrystal structure of Human NMPRTase as free-form
Structural highlights
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 PubMedNicotinamide (NM) phosphoribosyltransferase (NMPRTase) catalyzes the reaction of NM and 5'-phosphoribosyl-1'-pyrophosphate (PRPP) to form NM mononucleotide (NMN) and pyrophosphate (PPi) in the pathway of NAD-biosynthesis. Monitoring the (1)H and (31)P NMR spectra of the reaction mixture, we found that this reaction is reversible as dictated by the equilibrium constant K = [NMN][PPi]/([NM][PRPP]) = 0.14, which agreed well with the ratio of second-order rate constants for forward and backward reactions, K = 0.16. The crystal structures of this enzyme in the free form and bound to NM and PRPP at the resolution of 2.0-2.2 A were essentially identical to that of the complex with NMN, except for some variations that could facilitate the substitution reaction by fixing the nucleophile and the leaving group for the requisite inversion of configuration at the C1' carbon of the ribose ring. In the active site near the C1' atom of the bound PRPP or NMN, there was neither negatively charged group nor waterproof environment necessary to support the feasibility of a ribo-oxocarbocation intermediate inherent in the S(N)1 mechanism. The structures and catalytic mechanism thus revealed are also discussed in connection with the multiple biological functions of NMPRTase. Structure and reaction mechanism of human nicotinamide phosphoribosyltransferase.,Takahashi R, Nakamura S, Nakazawa T, Minoura K, Yoshida T, Nishi Y, Kobayashi Y, Ohkubo T J Biochem. 2010 Jan;147(1):95-107. Epub 2009 Oct 9. PMID:19819904[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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