1CI3

CYTOCHROME F FROM THE B6F COMPLEX OF PHORMIDIUM LAMINOSUM

Summary for 1CI3

• Entry DOI: 10.2210/pdb1ci3/pdb
• Descriptor: PROTEIN (CYTOCHROME F), ZINC ION, HEME C, ... (4 entities in total)
• Functional Keywords: electron transfer protein, complex subunit, electron transport
• Biological source: Phormidium laminosum
• Cellular location: Cellular thylakoid membrane; Single-pass membrane protein (By similarity): P95522
• Total number of polymer chains: 1
• Total formula weight: 27211.88

Authors

Carrell, C.J.,Schlarb, B.G.,Howe, C.J.,Bendall, D.S.,Cramer, W.A.,Smith, J.L. (deposition date: 1999-04-07, release date: 1999-08-11, Last modification date: 2024-11-06)

Primary citation

Carrell, C.J.,Schlarb, B.G.,Bendall, D.S.,Howe, C.J.,Cramer, W.A.,Smith, J.L.
Structure of the soluble domain of cytochrome f from the cyanobacterium Phormidium laminosum.
Biochemistry, 38:9590-9599, 1999

PubMed Abstract: Cytochrome f from the photosynthetic cytochrome b(6)f complex is unique among c-type cytochromes in its fold and heme ligation. The 1. 9-A crystal structure of the functional, extrinsic portion of cytochrome f from the thermophilic cyanobacterium Phormidium laminosum demonstrates that an unusual buried chain of five water molecules is remarkably conserved throughout the biological range of cytochrome f from cyanobacteria to plants [Martinez et al. (1994) Structure 2, 95-105]. Structure and sequence conservation of the cytochrome f extrinsic portion is concentrated at the heme, in the buried water chain, and in the vicinity of the transmembrane helix anchor. The electrostatic surface potential is variable, so that the surface of P. laminosum cytochrome f is much more acidic than that from turnip. Cytochrome f is unrelated to cytochrome c(1), its functional analogue in the mitochondrial respiratory cytochrome bc(1) complex, although other components of the b(6)f and bc(1) complexes are homologous. Identical function of the two complexes is inferred for events taking place at sites of strong sequence conservation. Conserved sites throughout the entire cytochrome b(6)f/bc(1) family include the cluster-binding domain of the Rieske protein and the heme b and quinone-binding sites on the electrochemically positive side of the membrane within the b cytochrome, but not the putative quinone-binding site on the electrochemically negative side.

PubMed: 10423236
DOI: 10.1021/bi9903190

Experimental method

X-RAY DIFFRACTION (1.9 Å)