TY - JOUR
T1 - Identification of the ferredoxin interaction sites on ferredoxin-dependent glutamate synthase from Synechocystis sp. PCC 6803
AU - Hirasawa, Masakazu
AU - Solis, Jacaranda
AU - Vaidyanathan, Nanditha
AU - Srivastava, Anurag P.
AU - Wynn, R. Max
AU - Sutton, Roger B.
AU - Knaff, David B.
N1 - Funding Information:
Acknowledgements We especially thank Prof. Guy Hanke (Queen Mary University of London) for reading this manuscript and suggesting layout of this manuscript. This research was supported by AR063634 (to R.B.S) and the Office of Basic Energy Sciences of the U.S. Department of Energy, through Grant DE-FG03-99ER20346 (to D.B.K.).
Publisher Copyright:
© 2017, Springer Science+Business Media B.V.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Based on in silico docking methods, five amino acids in glutamate synthase (Gln-467, His-1144, Asn-1147, Arg-1162, and Trp-676) likely constitute key binding residues in the interface of a glutamate synthase:ferredoxin complex. Although all interfacial mutants studied showed the ability to form a complex under low ionic strength, these docking mutations showed significantly less ferredoxin-dependent activities, while still retaining enzymatic activity. Furthermore, isothermal titration calorimetry showed a possible 1:2 molar ratio between the wild-type glutamate synthase and ferredoxin. However, each of our interfacial mutants showed only a 1:1 complex with ferredoxin, suggesting that the mutations directly affect the glutamate synthase:ferredoxin heterodimer interface.
AB - Based on in silico docking methods, five amino acids in glutamate synthase (Gln-467, His-1144, Asn-1147, Arg-1162, and Trp-676) likely constitute key binding residues in the interface of a glutamate synthase:ferredoxin complex. Although all interfacial mutants studied showed the ability to form a complex under low ionic strength, these docking mutations showed significantly less ferredoxin-dependent activities, while still retaining enzymatic activity. Furthermore, isothermal titration calorimetry showed a possible 1:2 molar ratio between the wild-type glutamate synthase and ferredoxin. However, each of our interfacial mutants showed only a 1:1 complex with ferredoxin, suggesting that the mutations directly affect the glutamate synthase:ferredoxin heterodimer interface.
KW - Electrostatic interactions
KW - Ferredoxin
KW - Flavin mononucleotide (FMN)
KW - Glutamate synthase
KW - In silico docking
KW - Iron–sulfur-binding sites
KW - Isothermal titration calorimetry
KW - Site-directed mutagenesis
KW - Spectral perturbation
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U2 - 10.1007/s11120-017-0446-z
DO - 10.1007/s11120-017-0446-z
M3 - Article
C2 - 28975508
AN - SCOPUS:85030320899
SN - 0166-8595
VL - 134
SP - 317
EP - 328
JO - Photosynthesis Research
JF - Photosynthesis Research
IS - 3
ER -