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| [[Image:1cbu.gif|left|200px]]<br /><applet load="1cbu" size="450" color="white" frame="true" align="right" spinBox="true"
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| caption="1cbu, resolution 2.3Å" />
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| '''ADENOSYLCOBINAMIDE KINASE/ADENOSYLCOBINAMIDE PHOSPHATE GUANYLYLTRANSFERASE (COBU) FROM SALMONELLA TYPHIMURIUM'''<br />
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| ==Overview== | | ==ADENOSYLCOBINAMIDE KINASE/ADENOSYLCOBINAMIDE PHOSPHATE GUANYLYLTRANSFERASE (COBU) FROM SALMONELLA TYPHIMURIUM== |
| The X-ray structure of adenosylcobinamide kinase/adenosylcobinamide, phosphate guanylyltransferase (CobU) from Salmonella typhimurium has been, determined to 2.3 A resolution. This enzyme of subunit molecular weight 19, 770 plays a central role in the assembly of the nucleotide loop for, adenosylcobalamin where it catalyzes both the phosphorylation of the, 1-amino-2-propanol side chain of the corrin ring and the subsequent, attachment of GMP to form the product adenosylcobinamide-GDP. The kinase, activity is believed to be associated with a P-loop motif, whereas the, transferase activity proceeds at a different site on the enzyme via a, guanylyl intermediate. The enzyme was crystallized in the space group, C2221 with unit cell dimensions of a = 96.4 A, b = 114.4 A, and c = 106.7, A, with three subunits per asymmetric unit. The structure reveals that the, enzyme is a molecular trimer and appears somewhat like a propeller with, overall molecular dimensions of approximately 64 A x 77 A x 131 A. Each, subunit consists of a single domain that is dominated by a seven-stranded, mixed beta-sheet flanked on either side by a total of five alpha-helices, and one helical turn. Six of the seven beta-strands run parallel. The, C-terminal strand lies at the edge of the sheet and runs antiparallel to, the others. Interestingly, CobU displays a remarkable structural and, topological similarity to the central domain of the RecA protein, although, the reason for this observation is unclear. The structure contains a, P-loop motif located at the base of a prominent cleft formed by the, association of two subunits and is most likely the kinase active site., Each subunit of CobU contains a cis peptide bond between Glu80 and Cys81, where Glu80 faces the P-loop and might serve to coordinate the magnesium, ion of the triphosphate substrate. Interestingly, His46, which is the, putative site for guanylylation, lies approximately 21 A from the P-loop, and is solvent-exposed. This suggests that the enzyme undergoes a, conformational change when the substrates bind to bring these two active, sites into closer proximity.
| | <StructureSection load='1cbu' size='340' side='right'caption='[[1cbu]], [[Resolution|resolution]] 2.30Å' scene=''> |
| | | == Structural highlights == |
| ==About this Structure== | | <table><tr><td colspan='2'>[[1cbu]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Salmonella_enterica_subsp._enterica_serovar_Typhimurium Salmonella enterica subsp. enterica serovar Typhimurium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CBU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CBU FirstGlance]. <br> |
| 1CBU is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Salmonella_typhimurium Salmonella typhimurium] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1CBU OCA].
| | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.3Å</td></tr> |
| | | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> |
| ==Reference== | | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1cbu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1cbu OCA], [https://pdbe.org/1cbu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1cbu RCSB], [https://www.ebi.ac.uk/pdbsum/1cbu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1cbu ProSAT]</span></td></tr> |
| Three-dimensional structure of adenosylcobinamide kinase/adenosylcobinamide phosphate guanylyltransferase from Salmonella typhimurium determined to 2.3 A resolution,., Thompson TB, Thomas MG, Escalante-Semerena JC, Rayment I, Biochemistry. 1998 May 26;37(21):7686-95. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=9601028 9601028]
| | </table> |
| [[Category: Salmonella typhimurium]] | | == Function == |
| [[Category: Single protein]] | | [https://www.uniprot.org/uniprot/COBU_SALTY COBU_SALTY] Catalyzes ATP-dependent phosphorylation of adenosylcobinamide and addition of GMP to adenosylcobinamide phosphate. |
| [[Category: Escalante-Semerena, J.C.]] | | == Evolutionary Conservation == |
| [[Category: Rayment, I.]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| [[Category: Thomas, M.G.]]
| | Check<jmol> |
| [[Category: Thompson, T.B.]] | | <jmolCheckbox> |
| [[Category: SO4]] | | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/cb/1cbu_consurf.spt"</scriptWhenChecked> |
| [[Category: adenosylcobinamide]] | | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| [[Category: atpase]]
| | <text>to colour the structure by Evolutionary Conservation</text> |
| [[Category: cobalamin biosynthesis]] | | </jmolCheckbox> |
| [[Category: coenzyme b12]] | | </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=1cbu ConSurf]. |
| [[Category: guanylyltransferase]] | | <div style="clear:both"></div> |
| [[Category: kinase]] | | __TOC__ |
| [[Category: salmonella typhimurium]] | | </StructureSection> |
| [[Category: transferase]] | | [[Category: Large Structures]] |
| | | [[Category: Salmonella enterica subsp. enterica serovar Typhimurium]] |
| ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 12:19:40 2007''
| | [[Category: Escalante-Semerena JC]] |
| | [[Category: Rayment I]] |
| | [[Category: Thomas MG]] |
| | [[Category: Thompson TB]] |
