Sandbox Reserved 335: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 6: | Line 6: | ||
'''Cytochrome ''c''''' (cyt ''c'') is a superfamily of proteins belonging to the class of [http://en.wikipedia.org/wiki/All-α_proteins all-α proteins] with a core of helices and a covalently-bound [http://en.wikipedia.org/wiki/Heme heme prosthetic group].<ref>PMID:11697912</ref><ref name=main /> The cytochrome ''c'' superfamily contains many different families including monodomain and multi-domain C-type cytochromes (ex. [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). This page focuses mainly on the cytochrome ''c'' superfamily, briefly discussing various types within the superfamily. The monoheme cytochrome ''c'' purified from ''Rhodothermus marinus'' will be discussed in greater detail than other C-type cytochromes. | '''Cytochrome ''c''''' (cyt ''c'') is a superfamily of proteins belonging to the class of [http://en.wikipedia.org/wiki/All-α_proteins all-α proteins] with a core of helices and a covalently-bound [http://en.wikipedia.org/wiki/Heme heme prosthetic group].<ref>PMID:11697912</ref><ref name=main /> The cytochrome ''c'' superfamily contains many different families including monodomain and multi-domain C-type cytochromes (ex. [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). This page focuses mainly on the cytochrome ''c'' superfamily, briefly discussing various types within the superfamily. The monoheme cytochrome ''c'' purified from ''Rhodothermus marinus'' (''Rm''cyt''c'') will be discussed in greater detail than other C-type cytochromes. | ||
== Introduction == | == Introduction == | ||
| Line 16: | Line 16: | ||
=== ''Rhodothermus marinus'' === | === ''Rhodothermus marinus'' === | ||
''Rhodothermus marinus'' is a Gram-negative bacterium in the class Sphingobacteria, in phylum Bacteroidetes. These bacteria are thermophilic, obligate aerobes that have been previously isolated from shallow-water submarine hot springs located in Iceland.<ref name="bacteria">Alfredsson GA, Kristjansson JK, Hjörleifsdottir S, Stetter, KO. Rhodothermus marinus, gen. nov., sp. nov., a thermophilic, halophilic bacterium from submarine hot springs in Iceland. J Gen Microbiol. 1988 Feb;134(2):299-306.</ref> A monoheme cytochrome ''c'' that has been thought to be the first member of a new class of cyt ''c'' was recently purified from ''R. marinus | ''Rhodothermus marinus'' is a Gram-negative bacterium in the class Sphingobacteria, in phylum Bacteroidetes. These bacteria are thermophilic, obligate aerobes that have been previously isolated from shallow-water submarine hot springs located in Iceland.<ref name="bacteria">Alfredsson GA, Kristjansson JK, Hjörleifsdottir S, Stetter, KO. Rhodothermus marinus, gen. nov., sp. nov., a thermophilic, halophilic bacterium from submarine hot springs in Iceland. J Gen Microbiol. 1988 Feb;134(2):299-306.</ref> A monoheme cytochrome ''c'' that has been thought to be the first member of a new class of cyt ''c'' was recently purified from ''R. marinus''.<ref name=main /> | ||
== Structure == | == Structure == | ||
| Line 22: | Line 22: | ||
<Structure load='3cp5' size='300' frame='true' align='right' caption='Insert caption here' scene='Sandbox_Reserved_335/Heme/1' /> | <Structure load='3cp5' size='300' frame='true' align='right' caption='Insert caption here' scene='Sandbox_Reserved_335/Heme/1' /> | ||
All members in the C-type cytochrome superfamily contain a heme prosthetic group that is covalently attached to the protein via two thioether bonds to cysteine residues; most cytochromes ''c'' occur in a <scene name='Sandbox_Reserved_335/Motif/1'>CXXCH motif</scene>, where a histidine residue is one of the two axial ligands of the heme iron.<ref name=main>PMID:18855424</ref><ref name=heme /> The other axial position, in monoheme cytochromes ''c'', may be left vacant or be occupied by histidine or methionine residues, but can sometimes be occupied by cysteine or leucine residues.<ref name=main />. The typical monoheme cyt ''c'' fold is formed by helices <scene name='Sandbox_Reserved_335/Helices/2'>A, C, and E</scene>. In ''Rm''cyt''c'' there are seven α-helices that are folded around the porphyrin ring, all connected by random coils.<ref name=main /> The heme group is axially coordinated by <scene name='Sandbox_Reserved_335/Axial/3'>His49 and Met100</scene> | All members in the C-type cytochrome superfamily contain a heme prosthetic group that is covalently attached to the protein via two thioether bonds to cysteine residues; most cytochromes ''c'' occur in a <scene name='Sandbox_Reserved_335/Motif/1'>CXXCH motif</scene>, where a histidine residue is one of the two axial ligands of the heme iron.<ref name=main>PMID:18855424</ref><ref name=heme /> In ''Rm''cyt''c'', XX represents a threonine and an alanine residue. The other axial position, in monoheme cytochromes ''c'', may be left vacant or be occupied by histidine or methionine residues, but can sometimes be occupied by cysteine or leucine residues.<ref name=main />. The typical monoheme cyt ''c'' fold is formed by helices <scene name='Sandbox_Reserved_335/Helices/2'>A, C, and E</scene>. In ''Rm''cyt''c'' there are seven α-helices that are folded around the porphyrin ring, all connected by random coils.<ref name=main /> The heme group is axially coordinated by <scene name='Sandbox_Reserved_335/Axial/3'>His49 and Met100</scene> | ||
