Crystal structure and possible dimerization of the high-potential iron-sulfur protein from Chromatium purpuratum.
The crystal structure of the high-potential iron-sulfur protein (HiPIP) isolated from Chromatium purpuratum is reported at 2.7 A resolution. The three HiPIP molecules in the asymmetric unit of the crystals form one and one-half dimers. Two molecules are related by a noncrystallographic symmetry rotation of approximately 175 degrees with negligible translation along the dyad axis. The third molecule in the asymmetric unit also forms a dimer with a second HiPIP molecule across the crystallographic 2-fold symmetry axis. The Fe4S4 clusters in both the crystallographic and noncrystallographic dimers are separated by approximately 13.0 A. Solution studies give mixed results regarding the oligomeric state of the C. purpuratum HiPIP. A comparison with crystal structures of HiPIPs from other species shows that HiPIP tends to associate rather nonspecifically about a conserved, relatively hydrophobic surface patch to form dimers.
Molecular Biology Institute, University of California at Los Angeles 90095-1570, USA.
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Kerfeld
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Salmeen
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Yeates
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D002844:Chromatium / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D008027:Light; D008958:Models, Molecular; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins; D017434:Protein Structure, Tertiary; D012542:Scattering, Radiation; D012996:Solutions; D014461:Ultracentrifugation
D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D012996:Solutions; C007943:high potential iron-sulfur protein