TY - JOUR
T1 - Characterization of the quinine reductase activity of the ferrice reductase B protein from Paracoccus denitrificans.
AU - Sedlacek, V.
AU - van Spanning, R.J.M.
AU - Kucera, I.
PY - 2009
Y1 - 2009
N2 - The ferric reductase B (FerB) protein of Paracoccus denitrificans exhibits activity of an NAD(P)H: Fe(III) chelate, chromate and quinone oxidoreductase. Sequence analysis places FerB in a family of soluble flavin-containing quinone reductases. The enzyme reduces a range of quinone substrates, including derivatives of 1,4-benzoquinone and 1,2- and 1,4-naphthoquinone, via a ping-pong kinetic mechanism. Dicoumarol and Cibacron Blue 3GA are competitive inhibitors of NADH oxidation. In the case of benzoquinones, FerB apparently acts through a two-electron transfer process, whereas in the case of naphthoquinones, one-electron reduction takes place resulting in the formation of semiquinone radicals. A ferB mutant strain exhibited an increased resistance to 1,4-naphthoquinone, attributable to the absence of the FerB-mediated redox cycling. The ferB promoter displayed a high basal activity throughout the growth of P. denitrificans, which could not be further enhanced by addition of different types of naphthoquinones. This indicates that the ferB gene is expressed constitutively. © 2008 Elsevier Inc. All rights reserved.
AB - The ferric reductase B (FerB) protein of Paracoccus denitrificans exhibits activity of an NAD(P)H: Fe(III) chelate, chromate and quinone oxidoreductase. Sequence analysis places FerB in a family of soluble flavin-containing quinone reductases. The enzyme reduces a range of quinone substrates, including derivatives of 1,4-benzoquinone and 1,2- and 1,4-naphthoquinone, via a ping-pong kinetic mechanism. Dicoumarol and Cibacron Blue 3GA are competitive inhibitors of NADH oxidation. In the case of benzoquinones, FerB apparently acts through a two-electron transfer process, whereas in the case of naphthoquinones, one-electron reduction takes place resulting in the formation of semiquinone radicals. A ferB mutant strain exhibited an increased resistance to 1,4-naphthoquinone, attributable to the absence of the FerB-mediated redox cycling. The ferB promoter displayed a high basal activity throughout the growth of P. denitrificans, which could not be further enhanced by addition of different types of naphthoquinones. This indicates that the ferB gene is expressed constitutively. © 2008 Elsevier Inc. All rights reserved.
U2 - 10.1016/j.abb.2008.12.016
DO - 10.1016/j.abb.2008.12.016
M3 - Article
SN - 0003-9861
VL - 483
SP - 29
EP - 36
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
ER -
