The interaction domain of the redox protein adrenodoxin is mandatory for binding of the electron acceptor CYP11A1, but is not required for binding of the electron donor adrenodoxin reductase

Journal Article · Fri Dec 09 04:00:00 EST 2005 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2005.0· OSTI ID:20793209

Heinz, Achim ^[1]; Hannemann, Frank ^[1]; Mueller, Juergen J ^[2]; Heinemann, Udo ^[2]; Bernhardt, Rita ^[1]

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1. FR 8.3-Biochemie, Universitaet des Saarlandes, D-66041 Saarbrucken (Germany)
2. FG Kristallographie, Max-Delbrueck-Center, Robert-Roessle-Str.10, D-13125 Berlin (Germany)

Adrenodoxin (Adx) is a [2Fe-2S] ferredoxin involved in electron transfer reactions in the steroid hormone biosynthesis of mammals. In this study, we deleted the sequence coding for the complete interaction domain in the Adx cDNA. The expressed recombinant protein consists of the amino acids 1-60, followed by the residues 89-128, and represents only the core domain of Adx (Adx-cd) but still incorporates the [2Fe-2S] cluster. Adx-cd accepts electrons from its natural redox partner, adrenodoxin reductase (AdR), and forms an individual complex with this NADPH-dependent flavoprotein. In contrast, formation of a complex with the natural electron acceptor, CYP11A1, as well as electron transfer to this steroid hydroxylase is prevented. By an electrostatic and van der Waals energy minimization procedure, complexes between AdR and Adx-cd have been proposed which have binding areas different from the native complex. Electron transport remains possible, despite longer electron transfer pathways.

• OSTI ID: 20793209
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 1 Vol. 338; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
AMINO ACIDS
BINDING ENERGY
BIOSYNTHESIS
COMPLEXES
ELECTRON TRANSFER
FERREDOXIN
HYDROXYLASES
MAMMALS
MINIMIZATION
NADP
STEROID HORMONES
STEROIDS
VALENCE
VAN DER WAALS FORCES