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 - 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 -