Metal ion modulated electron transfer in photosynthetic proteins.
Photosynthetic purple bacterial reaction center (RC) proteins are ideal native systems for addressing basic questions regarding the nature of biological electron transfer because both the protein structure and the electron-transfer reactions are well-characterized. Metal ion binding to the RC can affect primary photochemistry and provides a probe for understanding the involvement of local protein environments in electron transfer. The RC has two distinct transition metal ion binding sites, the well-known non-heme Fe(2+) site buried in the protein interior and a recently discovered Zn(2+) site located on the surface of the protein. Fe(2+) removal and Zn(2+) binding systematically affect different electron-transfer steps in the RC. Factors involved in the metal ion alteration of RC electron transfer may provide a paradigm for other biological systems involved in electron transfer.
Utschig
Lisa M
LM
Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Thurnauer
Marion C
MC
D001665:Binding Sites; D003300:Copper / Q000737:chemistry; D004579:Electron Transport; D004583:Electrons; D007501:Iron / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D011487:Protein Conformation; D018717:Purple Membrane / Q000737:chemistry; D012242:Rhodobacter sphaeroides / Q000737:chemistry; D013696:Temperature; D015032:Zinc / Q000737:chemistry
D008670:Metals; D045322:Photosynthetic Reaction Center Complex Proteins; D003300:Copper; D007501:Iron; D015032:Zinc