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6bme
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<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> | <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> | ||
</table> | </table> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == 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. | ||
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| + | 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> | ||
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| + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| + | </div> | ||
| + | <div class="pdbe-citations 6bme" style="background-color:#fffaf0;"></div> | ||
| + | |||
| + | ==See Also== | ||
| + | *[[Hemoglobin 3D structures|Hemoglobin 3D structures]] | ||
| + | == References == | ||
| + | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Revision as of 12:29, 16 January 2019
Crystal structure of Chlamydomonas reinhardtii THB4
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