6bme

<StructureSection load='6bme' size='340' side='right' caption='[[6bme]], [[Resolution|resolution]] 1.90&Aring;' scene=''>

<table><tr><td colspan='2'>[[6bme]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Chlre Chlre]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6BME OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6BME FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">THB4 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=3055 CHLRE])</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6bme FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6bme OCA], [http://pdbe.org/6bme PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6bme RCSB], [http://www.ebi.ac.uk/pdbsum/6bme PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6bme ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

BACKGROUND: The nuclear genome of Chlamydomonas reinhardtii encodes a dozen hemoglobins of the truncated lineage. Four of these, named THB1-4, contain a single ~130-residue globin unit. THB1, which is cytoplasmic and capable of nitric oxide dioxygenation activity, uses a histidine and a lysine as axial ligands to the heme iron. In the present report, we compared THB2, THB3, and THB4 to THB1 to gain structural and functional insights into algal globins. METHODS: We inspected properties of the globin domains prepared by recombinant means through site-directed mutagenesis, electronic absorption, CD, and NMR spectroscopies, and X-ray crystallography. RESULTS: Recombinant THB3, which lacks the proximal histidine but has a distal histidine, binds heme weakly. NMR data demonstrate that the recombinant domains of THB2 and THB4 coordinate the ferrous heme iron with the proximal histidine and a lysine from the distal helix. An X-ray structure of ferric THB4 confirms lysine coordination. THB1, THB2, and THB4 have reduction potentials between -65 and -100 mV, are capable of nitric oxide dioxygenation, are reduced at different rates by the diaphorase domain of C. reinhardtii nitrate reductase, and show different response to peroxide treatment. CONCLUSIONS: Three single-domain C. reinhardtii hemoglobins use lysine as a distal heme ligand in both Fe(III) and Fe(II) oxidation states. This common feature is likely related to enzymatic activity in the management of reactive oxygen species. GENERAL SIGNIFICANCE: Primary structure analysis of hemoglobins has limited power in the prediction of heme ligation. Experimental determination reveals variations in this essential property across the superfamily.

 

Lysine as a heme iron ligand: A property common to three truncated hemoglobins from Chlamydomonas reinhardtii.,Johnson EA, Russo MM, Nye DB, Schlessman JL, Lecomte JTJ Biochim Biophys Acta Gen Subj. 2018 Dec;1862(12):2660-2673. doi:, 10.1016/j.bbagen.2018.08.009. Epub 2018 Aug 10. PMID:30251657<ref>PMID:30251657</ref>

 

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 6bme" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Chlre]]

[[Category: Lecomte, J T.J]]

[[Category: Russo, M M]]

[[Category: Schlessman, J L]]

[[Category: 2-on-2 hemoglobin]]

[[Category: Truncated hemoglobin]]