X-ray Structure of a Truncated Form of Cytochrome f from Chlamydomonas reinhardtii
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- 作者：Young-In Chi ; Li-Shar Huang ; Zhaolei Zhang ; Javier G. Ferná ; ndez-Velasco ; and Edward A. Berry
- 刊名：Biochemistry
- 出版年：2000
- 出版时间：July 3, 2000
- 年：2000
- 卷：39
- 期：26
- 页码：7689 - 7701
- 全文大小：892K
- 年卷期：v.39,no.26(July 3, 2000)
- ISSN：1520-4995
文摘
A truncated form of cytochrome f from Chlamydomonas reinhardtii (an important eukaryoticmodel organism for photosynthetic electron transfer studies) has been crystallized (space group P212121;three molecules/asymmetric unit) and its structure determined to 2.0 Å resolution by molecular replacementusing the coordinates of a truncated turnip cytochrome f as a model. The structure displays the samefolding and detailed features as turnip cytochrome f, including (a) an unusual heme Fe ligation by the
-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 betweenthe heme pocket and K58 and K66 at the lysine cluster. For this array of waters, we propose a structuralrole. Two cytochrome f molecules are related by a noncrystallographic symmetry operator which is adistorted 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 orientedmembranes.
-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 betweenthe heme pocket and K58 and K66 at the lysine cluster. For this array of waters, we propose a structuralrole. Two cytochrome f molecules are related by a noncrystallographic symmetry operator which is adistorted 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 orientedmembranes.