PDBsum entry 1ci3

Electron transport

PDB id: 1ci3

Contents

Protein chain

249 a.a. *

Ligands

HEC

Metals

_ZN ×2

Waters ×250

* Residue conservation analysis

PDB id:

1ci3

Name:

Electron transport

Title:

Cytochrome f from the b6f complex of phormidium laminosum

Structure:

Protein (cytochrome f). Chain: m. Fragment: soluble extrinsic fragment. Engineered: yes. Other_details: thioether link between cys 21 and heme 254. Coordination of heme iron by his 25 and n-terminal amino group

Source:

Phormidium laminosum. Organism_taxid: 32059. Cellular_location: membrane-cytoplasm interface. Gene: peta. Expressed in: escherichia coli str. K12 substr. W3110. Expression_system_taxid: 316407.

Biol. unit:

Dimer (from PQS)

Resolution:

1.90Å R-factor: 0.203 R-free: 0.235

Authors:

C.J.Carrell,B.G.Schlarb,C.J.Howe,D.S.Bendall,W.A.Cramer,J.L.Smith

Key ref:

C.J.Carrell et al. (1999). Structure of the soluble domain of cytochrome f from the cyanobacterium Phormidium laminosum. Biochemistry, 38, 9590-9599. PubMed id: 10423236 DOI: 10.1021/bi9903190

Date:

07-Apr-99 Release date: 11-Aug-99

Protein chain

P95522  (CYF_LEPLM) -  Cytochrome f from Leptolyngbya laminosa

Seq: 338 a.a.

Struc: 249 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

DOI no: 10.1021/bi9903190

Biochemistry 38:9590-9599 (1999)

PubMed id: 10423236

Structure of the soluble domain of cytochrome f from the cyanobacterium Phormidium laminosum.

C.J.Carrell, B.G.Schlarb, D.S.Bendall, C.J.Howe, W.A.Cramer, J.L.Smith.

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.