View source for 1jhr


==Three-dimensional Structure of CobT in Complex with Reaction Products of 2-hydroxypurine and NaMN==
<StructureSection load='1jhr' size='340' side='right'caption='[[1jhr]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1jhr]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Salmonella_enterica Salmonella enterica]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JHR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1JHR FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NIO:NICOTINIC+ACID'>NIO</scene>, <scene name='pdbligand=P2P:N7-(5-PHOSPHO-ALPHA-RIBOSYL)-2-HYDROXYPURINE'>P2P</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1jhr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1jhr OCA], [https://pdbe.org/1jhr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1jhr RCSB], [https://www.ebi.ac.uk/pdbsum/1jhr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1jhr ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/COBT_SALTY COBT_SALTY] Catalyzes the synthesis of alpha-ribazole-5'-phosphate from nicotinate mononucleotide (NAMN) and 5,6-dimethylbenzimidazole (DMB).
== 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/jh/1jhr_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/main_output.php?pdb_ID=1jhr ConSurf].
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== Publication Abstract from PubMed ==
Nicotinate mononucleotide (NaMN):5,6-dimethylbenzimidazole phosphoribosyltransferase (CobT) from Salmonella enterica plays a central role in the synthesis of alpha-ribazole, a key component of the lower ligand of cobalamin. Surprisingly, CobT can phosphoribosylate a wide range of aromatic substrates, giving rise to a wide variety of lower ligands in cobamides. To understand the molecular basis for this lack of substrate specificity, the x-ray structures of CobT complexed with adenine, 5-methylbenzimidazole, 5-methoxybenzimidazole, p-cresol, and phenol were determined. Furthermore, adenine, 5-methylbenzimidazole, 5-methoxybenzimidazole, and 2-hydroxypurine were observed to react with NaMN within the crystal lattice and undergo the phosphoribosyl transfer reaction to form product. Significantly, the stereochemistries of all products are identical to those found in vivo. Interestingly, p-cresol and phenol, which are the lower ligand in Sporomusa ovata, bound to CobT but did not react with NaMN. This study provides a structural explanation for how CobT can phosphoribosylate most of the commonly observed lower ligands found in cobamides with the exception of the phenolic lower ligands observed in S. ovata. This is accomplished with minor conformational changes in the side chains that constitute the 5,6-dimethylbenzimidazole binding site. These investigations are consistent with the implication that the nature of the lower ligand is controlled by metabolic factors rather by the specificity of the phosphoribosyltransferase.

Structural investigation of the biosynthesis of alternative lower ligands for cobamides by nicotinate mononucleotide: 5,6-dimethylbenzimidazole phosphoribosyltransferase from Salmonella enterica.,Cheong CG, Escalante-Semerena JC, Rayment I J Biol Chem. 2001 Oct 5;276(40):37612-20. Epub 2001 Jul 5. PMID:11441022<ref>PMID:11441022</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Phosphoribosyltransferase 3D structures|Phosphoribosyltransferase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Salmonella enterica]]
[[Category: Cheong CG]]
[[Category: Escalante-Semerena J]]
[[Category: Rayment I]]