1cyj: Difference between revisions

[[Image:1cyj.jpg|left|200px]]<br /><applet load="1cyj" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

1CYJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Chlamydomonas_reinhardtii Chlamydomonas reinhardtii] with <scene name='pdbligand=CD:'>CD</scene> and <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CYJ OCA].  

[[Category: Kerfeld, C A.]]

[[Category: Yeates, T O.]]

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