MetaCyc Polypeptide: cytochrome b6-f complex subunit VIII

Gene: petN Accession Number: SYNPCC7942_0475 (MetaCyc)

Synonyms: Cytochrome b6-f complex subunit 8, Cytochrome b6-f complex subunit petN

Species: Synechococcus elongatus PCC 7942

Component of: cytochrome b6f complex (extended summary available)

PetN is one of the small subunits of the cytochrome b6-f complex, which mediates electron transfer between photosystem II (PSII) and photosystem I (PSI).

Locations: thylakoid membrane

Map Position: [460,449 <- 460,544]

Molecular Weight of Polypeptide: 3.67 kD (from nucleotide sequence)

Unification Links: NCBI Entrez Protein (GI):81168167 , Protein Model Portal:Q31R12 , SMR:Q31R12 , String:1140.Synpcc7942_0475 , UniProt:Q31R12

Relationship Links: InterPro:IN-FAMILY:IPR005497 , Pfam:IN-FAMILY:PF03742

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Cellular Component: GO:0042651 - thylakoid membrane


Revised 04-May-2011 by Weerasinghe D

Subunit of: cytochrome b6f complex

Species: Synechococcus elongatus PCC 7942

Subunit composition of cytochrome b6f complex = [PetA][PetB][PetN][PetG][PetD][PetM][PetC]
         apocytochrome f = PetA (summary available)
         cytochrome b6 = PetB (summary available)
         cytochrome b6-f complex subunit VIII = PetN (summary available)
         cytochrome b6-f complex subunit 5 = PetG (summary available)
         Cytochrome b6-f complex subunit 4 = PetD (summary available)
         Cytochrome b6-f complex subunit 7 = PetM (summary available)
         cytochrome b6-f complex iron-sulfur subunit = PetC (summary available)

The cytochrome b6-f complex connects electron transport between photosystem II (PSII) and photosystem I (PSI) and resides in the thylakoid membranes [Schwenkert07]. In cyanobacteria, it is present in both the thylakoid and cytoplasmic membranes [Schneider01]. Cytochrome b6-f is involved in state transition whereby it can migrate from the appressed region of the thylakoid membrane where PSII is located, to the non-appressed region which contains PSI [Iwai10]. In cyanobacteria the cytochrome b6f complex is an essential part of both the respiratory and the photosynthetic electron transport chains. The complex oxidizes plastoquinol and subsequently transfers electrons to the soluble electron carrier plastocyanin [Cape06].

The complex functions as a dimer and is composed of 4 large subunits, : apocytochrome f, cytochrome b6, cytochrome b6-f complex iron-sulfur subunit and Cytochrome b6-f complex subunit 4; and 4 small subunits, cytochrome b6-f complex subunit 5, PetL, Cytochrome b6-f complex subunit 7, and cytochrome b6-f complex subunit VIII [Schneider01]. PetL was found to be dispensible in Synechococcus elongatus PCC 7942 and the cyanobacterium Synechocystis sp. PCC 6803 [Schneider07].

Created 21-May-2008 by Caspi R , SRI International

Enzymatic reaction of: plastoquinol-plastocyanin reductase (cytochrome b6f complex)

EC Number:

Transport reaction diagram for plastoquinol-plastocyanin reductase

In Pathways: ethylene biosynthesis V (engineered) , 1-butanol autotrophic biosynthesis , oxygenic photosynthesis , photosynthesis light reactions


Cape06: Cape JL, Bowman MK, Kramer DM (2006). "Understanding the cytochrome bc complexes by what they don't do. The Q-cycle at 30." Trends Plant Sci 11(1);46-55. PMID: 16352458

Iwai10: Iwai M, Takizawa K, Tokutsu R, Okamuro A, Takahashi Y, Minagawa J (2010). "Isolation of the elusive supercomplex that drives cyclic electron flow in photosynthesis." Nature 464(7292);1210-3. PMID: 20364124

Schneider01: Schneider D, Berry S, Rich P, Seidler A, Rogner M (2001). "A regulatory role of the PetM subunit in a cyanobacterial cytochrome b6f complex." J Biol Chem 276(20);16780-5. PMID: 11278512

Schneider07: Schneider D, Volkmer T, Rogner M (2007). "PetG and PetN, but not PetL, are essential subunits of the cytochrome b6f complex from Synechocystis PCC 6803." Res Microbiol 158(1);45-50. PMID: 17224258

Schwenkert07: Schwenkert S, Legen J, Takami T, Shikanai T, Herrmann RG, Meurer J (2007). "Role of the low-molecular-weight subunits PetL, PetG, and PetN in assembly, stability, and dimerization of the cytochrome b6f complex in tobacco." Plant Physiol 144(4);1924-35. PMID: 17556510

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Tue Oct 13, 2015, biocyc12.