1cfm
CYTOCHROME F FROM CHLAMYDOMONAS REINHARDTII
OverviewOverview
A truncated form of cytochrome f from Chlamydomonas reinhardtii (an important eukaryotic model organism for photosynthetic electron transfer studies) has been crystallized (space group P2(1)2(1)2(1); three molecules/asymmetric unit) and its structure determined to 2.0 A resolution by molecular replacement using the coordinates of a truncated turnip cytochrome f as a model. The structure displays the same folding and detailed features as turnip cytochrome f, including (a) an unusual heme Fe ligation by the alpha-amino group of tyrosine 1, (b) a cluster of lysine residues (proposed docking site of plastocyanin), and (c) the presence of a chain of seven water molecules bound to conserved residues and extending between the heme pocket and K58 and K66 at the lysine cluster. For this array of waters, we propose a structural role. Two cytochrome f molecules are related by a noncrystallographic symmetry operator which is a distorted proper 2-fold rotation. This may represent the dimeric relation of the monomers in situ; however, the heme orientation suggested by this model is not consistent with previous EPR measurements on oriented membranes.
About this StructureAbout this Structure
1CFM is a Single protein structure of sequence from Chlamydomonas reinhardtii. Full crystallographic information is available from OCA.
ReferenceReference
X-ray structure of a truncated form of cytochrome f from chlamydomonas reinhardtii., Chi YI, Huang LS, Zhang Z, Fernandez-Velasco JG, Berry EA, Biochemistry. 2000 Jul 4;39(26):7689-701. PMID:10869174 Page seeded by OCA on Fri May 2 12:41:01 2008