View source for 1lt0


==Crystal structure of the CN-bound BjFixL heme domain==
<StructureSection load='1lt0' size='340' side='right'caption='[[1lt0]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1lt0]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bradyrhizobium_japonicum Bradyrhizobium japonicum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LT0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1LT0 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CYN:CYANIDE+ION'>CYN</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</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=1lt0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1lt0 OCA], [https://pdbe.org/1lt0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1lt0 RCSB], [https://www.ebi.ac.uk/pdbsum/1lt0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1lt0 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/FIXL_BRADU FIXL_BRADU] Putative oxygen sensor; modulates the activity of FixJ, a transcriptional activator of nitrogen fixation fixK gene. FixL probably acts as a kinase that phosphorylates FixJ.
== 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/lt/1lt0_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1lt0 ConSurf].
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== Publication Abstract from PubMed ==
Structures of the Bradyrhizobium japonicum FixL heme domain have been determined in the absence and presence of specific ligands to elucidate the detailed features of its O2 sensing mechanism. The putative roles of spin-state and steric hindrance were evaluated by the structure determination of ferrous CO-bound BjFixLH and correlating its features with other ligand-bound structures. As found for NO-BjFixLH, no protein conformational change was observed in CO-BjFixLH, suggesting a more complicated mechanism than solely spin state or ligand sterics. To evaluate the role of oxidation state, the structure of the ferrous deoxy-BjFixLH was determined. The structure of deoxy-BjFixLH was found to be virtually identical to the structure of the ferric met-BjFixLH. The role of hydrogen bonding of substrates to a heme-pocket water was evaluated by determining the structure of BjFixLH bound to 1-methyl-imidazole that cannot form a hydrogen bond with this water. In this case, the heme-mediated conformational change was observed, limiting the potential importance of this interaction. Finally, the structure of cyanomet-BjFixLH was revisited to rule out concerns regarding the partial occupancy of the cyanide ligand in a previous structure. In the revised structure, Arg 220 was found to move into the heme pocket to form a hydrogen bond to the bound cyanide ligand. The implications of these results on FixL's sensing mechanism are discussed.

Structure-based mechanism of O2 sensing and ligand discrimination by the FixL heme domain of Bradyrhizobium japonicum.,Hao B, Isaza C, Arndt J, Soltis M, Chan MK Biochemistry. 2002 Oct 29;41(43):12952-8. PMID:12390021<ref>PMID:12390021</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bradyrhizobium japonicum]]
[[Category: Large Structures]]
[[Category: Arndt J]]
[[Category: Chan MK]]
[[Category: Hao B]]
[[Category: Isaza C]]
[[Category: Soltis M]]