Cytochrome c: Difference between revisions
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<StructureSection load='' size='350' side='right' scene='Cytochrome_c/Cyt_c/1' caption='Cytochrome c with heme complex with sulfate (PDB code [[3cp5]])'> | <StructureSection load='' size='350' side='right' scene='Cytochrome_c/Cyt_c/1' caption='Cytochrome c with heme complex with sulfate (PDB code [[3cp5]])'> | ||
The '''cytochrome ''c''''' (cyt ''c'') proteins are a superfamily belonging to the class of [http://en.wikipedia.org/wiki/All-α_proteins all-α proteins], which are denoted as such by having an α-helical core. Each protein in this superfamily also contains one or more covalently-bound [http://en.wikipedia.org/wiki/Heme heme prosthetic groups].<ref>PMID:11697912</ref><ref name=main /> The cyt ''c'' superfamily contains many different families, some of which are better characterized than others. These families include monodomain and multi-domain C-type cytochromes, such as [http://proteopedia.org/wiki/index.php/1etp cyt c4], a diheme C-type cytochrome, and [http://proteopedia.org/wiki/index.php/2ozy NrfB], a pentaheme C-type cytochrome. In particular, the monoheme cyt ''c'' from ''Rhodothermus marinus'' has been previously studied and provides an excellent example of how some protein characteristics and structures can be extremely diverse, yet conserved, through evolution.<br /> For details on decaheme cyt see [[MtrF]].<br /> For details on Cyt c7 see [[Cytochrome c 7]].<br /> | The '''cytochrome ''c''''' (cyt ''c'') proteins are a superfamily belonging to the class of [http://en.wikipedia.org/wiki/All-α_proteins all-α proteins], which are denoted as such by having an α-helical core. Each protein in this superfamily also contains one or more covalently-bound [http://en.wikipedia.org/wiki/Heme heme prosthetic groups].<ref>PMID:11697912</ref><ref name=main /> The cyt ''c'' superfamily contains many different families, some of which are better characterized than others. These families include monodomain and multi-domain C-type cytochromes, such as [http://proteopedia.org/wiki/index.php/1etp cyt c4], a diheme C-type cytochrome, and [http://proteopedia.org/wiki/index.php/2ozy NrfB], a pentaheme C-type cytochrome. In particular, the monoheme cyt ''c'' from ''Rhodothermus marinus'' has been previously studied and provides an excellent example of how some protein characteristics and structures can be extremely diverse, yet conserved, through evolution.<br /> For details on decaheme cyt see [[MtrF]].<br /> For details on Cyt c7 see [[Cytochrome c 7]].<br /> | ||
*'''Cytochrome c2''' transfers electron from the reduced heme to the bacteriochlorophyl in the reaction centre<ref> PMID 15977062</ref>. | |||
*'''Cytochrome c3''' is specific to anaerobic metabolism in sulphate-reducing bacteria<ref> PMID 12885397</ref>. | |||
See also [[Cytochrome C -Adis]], [[Hemeproteins]], [[Cytochrome C (Hebrew)]], [[Cytochrome C (arabic)]]. | See also [[Cytochrome C -Adis]], [[Hemeproteins]], [[Cytochrome C (Hebrew)]], [[Cytochrome C (arabic)]]. | ||
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Cyt ''c'' has been split into four classes.<ref name=amb>PMID:1646017</ref> Class I contains soluble, low spin<ref name=main /> single domain C-type cytochromes, of which there has been at least six subclasses found in prokaryotes including [http://en.wikipedia.org/wiki/Desulfovibrio ''Desulfovibrio desulfuricans''], [http://en.wikipedia.org/wiki/Rhodospirillum_rubrum ''Rhodospirillum rubrum''], and ''Rhodothermus marinus''. Cyt ''c'' in this class have a single heme attached close to the N-terminus of the polypeptide, with a methionine residue being the sixth iron coordination site. Class II contains higher spin-state cytochromes ''c'', such as cyt ''c''', with the heme being attached closer to the C-terminus. Class III contains cytochromes with multiple heme groups; these proteins have lower redox potentials compared to the other three classes<ref name=amb />. Finally, Class IV is comprised of more complex proteins with higher molecular weights containing heme ''c'' as well as other prosthetic groups.<ref name=class>Cookson DJ, Moore GR, Pitt RC, Williams RJP, Campbell ID, Ambler RP, Bruschi M, Le Gall J. Structural homology of cytochromes c. Eur J Biochem. 1978 Feb;83(1):261-75.</ref> | Cyt ''c'' has been split into four classes.<ref name=amb>PMID:1646017</ref> Class I contains soluble, low spin<ref name=main /> single domain C-type cytochromes, of which there has been at least six subclasses found in prokaryotes including [http://en.wikipedia.org/wiki/Desulfovibrio ''Desulfovibrio desulfuricans''], [http://en.wikipedia.org/wiki/Rhodospirillum_rubrum ''Rhodospirillum rubrum''], and ''Rhodothermus marinus''. Cyt ''c'' in this class have a single heme attached close to the N-terminus of the polypeptide, with a methionine residue being the sixth iron coordination site. Class II contains higher spin-state cytochromes ''c'', such as cyt ''c''', with the heme being attached closer to the C-terminus. Class III contains cytochromes with multiple heme groups; these proteins have lower redox potentials compared to the other three classes<ref name=amb />. Finally, Class IV is comprised of more complex proteins with higher molecular weights containing heme ''c'' as well as other prosthetic groups.<ref name=class>Cookson DJ, Moore GR, Pitt RC, Williams RJP, Campbell ID, Ambler RP, Bruschi M, Le Gall J. Structural homology of cytochromes c. Eur J Biochem. 1978 Feb;83(1):261-75.</ref> | ||
== ''Rhodothermus marinus'' cytochrome ''c'' == | == ''Rhodothermus marinus'' cytochrome ''c'' == | ||