Citocromo f: Diferenzas entre revisións
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O '''citocromo ''f''''' (cyt f) é a subunidade máis grande do [[complexo do citocromo b6f|complexo do citocromo ''b''<sub>6</sub>''f'']] (plastoquinol—plastocianina redutase; [[ |
O '''citocromo ''f''''' (cyt f) é a subunidade máis grande do [[complexo do citocromo b6f|complexo do citocromo ''b''<sub>6</sub>''f'']] (plastoquinol—plastocianina redutase; [[número EC]] 1.10.99.1). Na súa estrutura e funcións, o complexo do citocromo b6f presenta unha grande analoxía co [[complexo do citocromo bc1]] da [[mitocondria]] e das [[bacterias fotosintéticas púrpuras]]. O citocromo f xoga un papel similar ao do citocromo c1, a pesar da súa [[estrutura secundaria das proteínas|estrutura secundaria]] diferente.<ref name="pmid7631417">{{cite journal | author = Prince RC, George GN | title = Cytochrome f revealed | journal = Trends Biochem. Sci. | volume = 20 | issue = 6 | pages = 217–8 |date=June 1995 | pmid = 7631417 | doi = | url = }}</ref> |
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⚫ | Determinouse a estrutura tridimensional do citocromo f de ''Brassica rapa'' ([[nabo]]).<ref name="pmid8762139">{{cite journal | author = Martinez SE, Huang D, Ponomarev M, Cramer WA, Smith JL | title = The heme redox center of chloroplast cytochrome f is linked to a buried five-water chain | journal = Protein Sci. | volume = 5 | issue = 6 | pages = 1081–92 |date=June 1996 | pmid = 8762139 | pmc = 2143431 | doi = 10.1002/pro.5560050610 | url = }}</ref> The lumen-side segment of cyt f includes two [[secondary structure|structural]] domains: a small one above a larger one that, in turn, is on top of the attachment to the membrane domain. The large domain consists of an anti-parallel beta-sandwich and a short haem-binding peptide, which form a three-layer [[protein structure|structure]]. The small domain is inserted between beta-strands F and G of the large domain and is an all-beta domain. The haem nestles between two short [[Alpha helix|helices]] at the N terminus of cyt f. Within the second [[helix]] is the [[sequence motif]] for the c-type cytochromes, CxxCH (residues 21-25), which is [[covalently]] attached to the haem through thioether [[Chemical bond|bond]]s to Cys-21 and Cys-24. His-25 is the fifth haem [[iron]] [[ligand (biochemistry)|ligand]]. The sixth haem iron [[Ligand (biochemistry)|ligand]] is the alpha-amino group of Tyr-1 in the first helix.<ref name="pmid8762139">{{cite journal | author = Martinez SE, Huang D, Ponomarev M, Cramer WA, Smith JL | title = The heme redox center of chloroplast cytochrome f is linked to a buried five-water chain | journal = Protein Sci. | volume = 5 | issue = 6 | pages = 1081–92 |date=June 1996 | pmid = 8762139 | pmc = 2143431 | doi = 10.1002/pro.5560050610 | url = }}</ref> Cyt f has an internal network of [[water]] molecules that may function as a proton wire.<ref name="pmid8762139">{{cite journal | author = Martinez SE, Huang D, Ponomarev M, Cramer WA, Smith JL | title = The heme redox center of chloroplast cytochrome f is linked to a buried five-water chain | journal = Protein Sci. | volume = 5 | issue = 6 | pages = 1081–92 |date=June 1996 | pmid = 8762139 | pmc = 2143431 | doi = 10.1002/pro.5560050610 | url = }}</ref> The water [[polymer|chain]] appears to be a [[conserved sequence|conserved]] feature of cyt f. |
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==Notas== |
==Notas== |
Revisión como estaba o 28 de febreiro de 2014 ás 17:22
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Apocytochr_F_C | |||||||||
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O citocromo f do complexo b6f de Phormidium laminosum | |||||||||
Identificadores | |||||||||
Símbolo | Apocytochr_F_C | ||||||||
Pfam | PF01333 | ||||||||
Pfam clan | CL0105 | ||||||||
InterPro | IPR002325 | ||||||||
PROSITE | PDOC00169 | ||||||||
SCOPe | 1ctm / SUPFAM | ||||||||
TCDB | 3.D.3 | ||||||||
OPM superfamily | 345 | ||||||||
OPM protein | 3h1j | ||||||||
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O citocromo f (cyt f) é a subunidade máis grande do complexo do citocromo b6f (plastoquinol—plastocianina redutase; número EC 1.10.99.1). Na súa estrutura e funcións, o complexo do citocromo b6f presenta unha grande analoxía co complexo do citocromo bc1 da mitocondria e das bacterias fotosintéticas púrpuras. O citocromo f xoga un papel similar ao do citocromo c1, a pesar da súa estrutura secundaria diferente.[1]
Determinouse a estrutura tridimensional do citocromo f de Brassica rapa (nabo).[2] The lumen-side segment of cyt f includes two structural domains: a small one above a larger one that, in turn, is on top of the attachment to the membrane domain. The large domain consists of an anti-parallel beta-sandwich and a short haem-binding peptide, which form a three-layer structure. The small domain is inserted between beta-strands F and G of the large domain and is an all-beta domain. The haem nestles between two short helices at the N terminus of cyt f. Within the second helix is the sequence motif for the c-type cytochromes, CxxCH (residues 21-25), which is covalently attached to the haem through thioether bonds to Cys-21 and Cys-24. His-25 is the fifth haem iron ligand. The sixth haem iron ligand is the alpha-amino group of Tyr-1 in the first helix.[2] Cyt f has an internal network of water molecules that may function as a proton wire.[2] The water chain appears to be a conserved feature of cyt f.
Notas
- ↑ Prince RC, George GN (June 1995). "Cytochrome f revealed". Trends Biochem. Sci. 20 (6): 217–8. PMID 7631417.
- ↑ 2,0 2,1 2,2 Martinez SE, Huang D, Ponomarev M, Cramer WA, Smith JL (June 1996). "The heme redox center of chloroplast cytochrome f is linked to a buried five-water chain". Protein Sci. 5 (6): 1081–92. PMC 2143431. PMID 8762139. doi:10.1002/pro.5560050610.
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Outros artigos
Outras lecturas
- Bendall, D.S. (2004). "The unfinished story of cytochrome f". Photosynth. Res. 80 (1–3): 265–276. PMID 16328825. doi:10.1023/B:PRES.0000030454.23940.f9.
- Cramer, W.A., Martinez, S.E., Huang, D., Tae, G.S., Everly, R.M., Heymann, J.B., Cheng, R.H., Baker, T.S. and Smith, J.L. (1994). "Structural aspects of the cytochrome b6f complex; structure of the lumen-side domain of cytochrome f". J. Bioenerg. Biomembr. 26 (1): 31–47. PMID 8027021. doi:10.1007/BF00763218.
Ligazóns externas
- Cytochrome f Medical Subject Headings (MeSH) na Biblioteca Nacional de Medicina dos EUA.
- Este artigo incorpora contidos en dominio publico de InterPro IPR002325.