Sandbox Reserved 1600: Difference between revisions
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One potential proton pathway is formed from the <scene name='83/838655/Bdoxidase_helix_a_1-4/1'>four-helix bundle (a1-4)</scene> of <scene name='83/838655/Bdoxidase_cyda_subunit/2'>CydA</scene>. It is called the <scene name='83/838655/Bdoxidase_cyda_pathway_glu108/1'>CydA pathway</scene>. The residues along this pathway help facilitate the movement of the protons. The location and negative charge characteristic of <scene name='83/838655/Bdoxidase_cyda_pathway_glu108/2'>Glu108</scene>, together with previous mutagenesis experiments, supports the proposal that this glutamate residue is a redox state-dependent mediator of proton transfer to a charge compensation site. In other words, it acts like a proton shuttle.<ref name =”Safarian” /> The <scene name='83/838655/Bdoxidase_cyda_pathway_glu101/1'>Glu101 residue</scene>, which is the last residue in this pathway, could be the protonatable group eventually used upon <scene name='83/838655/Bd_oxidase_heme_b_595/2'>Heme B595</scene> reduction. More research needs to be done to determine whether the CydA pathway is solely providing protons for charge compensation, or whether <scene name='83/838655/Bdoxidase_cyda_pathway_glu108/2'>Glu108</scene> can be a branching point that is able to pass protons via the <scene name='83/838655/Bd_oxidase_heme_b_595/2'>Heme B595</scene> propionates to the oxygen-binding site.<ref name=”Safarian”>PMID:27126043</ref> | One potential proton pathway is formed from the <scene name='83/838655/Bdoxidase_helix_a_1-4/1'>four-helix bundle (a1-4)</scene> of <scene name='83/838655/Bdoxidase_cyda_subunit/2'>CydA</scene>. It is called the <scene name='83/838655/Bdoxidase_cyda_pathway_glu108/1'>CydA pathway</scene>. The residues along this pathway help facilitate the movement of the protons. The location and negative charge characteristic of <scene name='83/838655/Bdoxidase_cyda_pathway_glu108/2'>Glu108</scene>, together with previous mutagenesis experiments, supports the proposal that this glutamate residue is a redox state-dependent mediator of proton transfer to a charge compensation site. In other words, it acts like a proton shuttle.<ref name =”Safarian” /> The <scene name='83/838655/Bdoxidase_cyda_pathway_glu101/1'>Glu101 residue</scene>, which is the last residue in this pathway, could be the protonatable group eventually used upon <scene name='83/838655/Bd_oxidase_heme_b_595/2'>Heme B595</scene> reduction. More research needs to be done to determine whether the CydA pathway is solely providing protons for charge compensation, or whether <scene name='83/838655/Bdoxidase_cyda_pathway_glu108/2'>Glu108</scene> can be a branching point that is able to pass protons via the <scene name='83/838655/Bd_oxidase_heme_b_595/2'>Heme B595</scene> propionates to the oxygen-binding site.<ref name=”Safarian”>PMID:27126043</ref> | ||
Another potential entry site is | Another potential entry site is close to the <scene name='83/838655/Bdoxidase_cydb_subunit_b1-4/1'>a1-4 four-helix bundle</scene> of <scene name='83/838655/Bdoxidase_cydb_subunit/2'>CydB</scene> and is referred to as the <scene name='83/838655/Bdoxidase_cydb_pathway/3'>CydB pathway</scene>. In this pathway, <scene name='83/838655/Bdoxidase_cydb_pathway_asp25/1'>Asp25</scene> is thought to be the equivalent of the <scene name='83/838655/Bdoxidase_cyda_pathway_glu108/2'>Glu108</scene> in the CydA pathway.<ref name =”Safarian” /> The other residues help facilitate the movement of the proton very similarly to the <scene name='83/838655/Bdoxidase_cyda_pathway_glu108/1'>CydA pathway</scene>. The <scene name='83/838655/Bdoxidase_cyda_pathway_glu108/1'>CydA pathway</scene> is the most accepted source of protons as less is known about the <scene name='83/838655/Bdoxidase_cydb_pathway/3'>CydB pathway</scene>. | ||
= Overall Oxygen Reduction Mechanism Summary= | = Overall Oxygen Reduction Mechanism Summary= | ||
