Identification of genes essential for the biogenesis of quinohemoprotein amine dehydrogenase.
The structural genes encoding quinohemoprotein amine dehydrogenase (QHNDH) in Gram-negative bacteria constitute a polycistronic operon together with several nearby genes, which are collectively termed "qhp". We previously showed that the qhpD gene, which lies between qhpA and qhpC (encoding the α and γ subunits of QHNDH, respectively), and the qhpE gene, which follows qhpB (encoding the β subunit), both encode enzymes specifically involved in the posttranslational modification of the γ subunit and are hence essential for QHNDH biogenesis in Paracoccus denitrificans [Ono, K., et al. (2006) J. Biol. Chem. 281, 13672-13684; Nakai, T., et al. (2012) J. Biol. Chem. 287, 6530-6538]. Here we further demonstrate that the qhpF gene, which follows qhpE, and the qhpG and qhpR genes, peripherally located in the complementary strand, are also indispensable for QHNDH biogenesis. The qhpF gene encodes an efflux ABC transporter, which probably translocates the γ subunit into the periplasm in a process coupled with hydrolysis of ATP. The qhpG gene encodes a putative FAD-dependent monooxygenase, which is required for the generation of the quinone cofactor in the γ subunit. Finally, the qhpR gene encodes an AraC family transcriptional regulator, which activates expression of the qhp operon in response to the addition of n-butylamine to the culture medium. Database analysis of the qhp genes reveals that they are very widely distributed, not only in many Gram-negative species but also in a few Gram-positive bacteria.
Department of Structural Molecular Biology, Institute of Scientific and Industrial Research, Osaka University , Ibaraki, Osaka 567-0047, Japan.
Tadashi
T
Nakai
Takafumi
T
Deguchi
Ivo
I
Frébort
Katsuyuki
K
Tanizawa
Toshihide
T
Okajima
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002082:Butylamines / Q000494:pharmacology; D030541:Databases, Genetic; D005798:Genes, Bacterial; D006090:Gram-Negative Bacteria / Q000201:enzymology / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D009876:Operon; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics* / Q000378:metabolism; D019897:Periplasm / Q000378:metabolism; D011401:Promoter Regions, Genetic; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D015533:Transcriptional Activation
D001426:Bacterial Proteins; D002082:Butylamines; D021122:Protein Subunits; D000587:Oxidoreductases Acting on CH-NH Group Donors; C119497:quinohemoprotein amine dehydrogenase; C032462:n-butylamine