Complex III of Electron Transport Chain: Difference between revisions

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Karl Oberholser, Eran Hodis, Jaime Prilusky, Alexander Berchansky, Michal Harel

Revision as of 00:36, 23 January 2009 view source Karl Oberholser (talk \| contribs) 1,665 edits No edit summary ← Older edit		Revision as of 22:33, 23 January 2009 view source Karl Oberholser (talk \| contribs) 1,665 edits No edit summary Newer edit →
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	== Structure of three active components ==		== Structure of three active components ==
	Each cytochrome b contains<scene name='Complex_III_of_Electron_Transport_Chain/Hem_cyto_b/2'> two hemes</scene>. Identify each of the hemes by hovering the curser over an atom of the heme. Hem 501 and Hem 502 are in one cytochrome b, and Hem 521 and Hem 522 are in the other one. The two hemes in each cytochrome b are in different environments and therefore have different properties, e.g. reduction potential. Hemes 501 & 521 have a lower potential than the other two and are called b<sub>L</sub> for low potential, and the other two are called b<sub>H</sub> for high potential. Each of the cytochrome b's have two binding sites for substrate. Ubiquinol binds at one of the sites, Q<sub>P</sub>, and the inhibitor stigmatellin binds at this site in both cytochrome b's (~~as shown~~ in the ~~second~~ applet below)(<scene name='Complex_III_of_Electron_Transport_Chain/Sma_cyto_b/1' target='second'>return to view of the inhibitor stigmatellin</scene>), and the site is adjacent to the b<sub>L</sub> heme. The other site, Q<sub>N</sub>, binds [[Coenzyme_Q10\|ubiquinone]], and <scene name='Complex_III_of_Electron_Transport_Chain/Surface_qn/2' name='second'>this surface</scene> outlines the site which is adjacent to the b<sub>H</sub> heme. antimycin A.		Each cytochrome b contains<scene name='Complex_III_of_Electron_Transport_Chain/Hem_cyto_b/2'> two hemes</scene>. Identify each of the hemes by hovering the curser over an atom of the heme. Hem 501 and Hem 502 are in one cytochrome b, and Hem 521 and Hem 522 are in the other one. The two hemes in each cytochrome b are in different environments and therefore have different properties, e.g. reduction potential. Hemes 501 & 521 have a lower potential than the other two and are called b<sub>L</sub> for low potential, and the other two are called b<sub>H</sub> for high potential. Each of the cytochrome b's have two binding sites for substrate. Ubiquinol binds at one of the sites, Q<sub>P</sub>, and the inhibitor stigmatellin binds at this site in both cytochrome b's (<scene name='Complex_III_of_Electron_Transport_Chain/Sma_blink_cyto_b/2' target='second'>Blink stigmatellin</scene> in the applet below)(<scene name='Complex_III_of_Electron_Transport_Chain/Sma_cyto_b/1' target='second'>return to view of the inhibitor stigmatellin</scene>), and the site is adjacent to the b<sub>L</sub> heme. The other site, Q<sub>N</sub>, binds [[Coenzyme_Q10\|ubiquinone]], and <scene name='Complex_III_of_Electron_Transport_Chain/Surface_qn/2' name='second'>this surface</scene> outlines the site which is adjacent to the b<sub>H</sub> heme. antimycin A.