1CYI

CYTOCHROME C6

Summary for 1CYI

• Entry DOI: 10.2210/pdb1cyi/pdb
• Descriptor: CYTOCHROME C6, CADMIUM ION, HEME C, ... (4 entities in total)
• Functional Keywords: photosynthesis, chlamydomonas, electron transport protein (cytochrome)
• Biological source: Chlamydomonas reinhardtii
• Cellular location: Plastid, chloroplast thylakoid lumen: P08197
• Total number of polymer chains: 1
• Total formula weight: 10879.14

Authors

Kerfeld, C.A.,Yeates, T.O. (deposition date: 1995-05-09, release date: 1996-01-29, Last modification date: 2024-10-30)

Primary citation

Kerfeld, C.A.,Anwar, H.P.,Interrante, R.,Merchant, S.,Yeates, T.O.
The structure of chloroplast cytochrome c6 at 1.9 A resolution: evidence for functional oligomerization.
J.Mol.Biol., 250:627-647, 1995

PubMed Abstract: The molecular structure of cytochrome c6 from the green alga Chlamydomonas reinhardtii has been determined from two crystal forms and refined to 1.9 A resolution. The two crystal forms are likely the result of different levels of post-translational modification of the protein. This is the first report of a high-resolution structure of a chloroplast-derived class I c-type cytochrome. The overall fold is similar to that of other class I c-type cytochromes, consisting of a series of alpha-helices and turns that envelop the heme prosthetic group. There is also a short two-stranded anti-parallel beta-sheet in the vicinity of the methionine axial ligand to the heme; this region of the molecule is formed by the most highly conserved residues in c6-type cytochromes. Although class I c-type cytochromes are assumed to function as monomers, both crystal forms of cytochrome c6 exhibit oligomerization about the heme crevice that is, in part, mediated by the short anti-parallel beta-sheet. The functional significance of this oligomerization is supported by the appearance of similar interfaces in other electron transfer couples, HPLC and light-scattering data, and is furthermore consistent with kinetic data on electron transfer reactions of c6-type cytochromes.

PubMed: 7623381
DOI: 10.1006/jmbi.1995.0404

Experimental method

X-RAY DIFFRACTION (1.9 Å)