Ligand specificity of MobR, a transcriptional regulator for the 3-hydroxybenzoate hydroxylase gene of Comamonas testosteroni KH122-3s

Journal Article · Fri Oct 19 04:00:00 EDT 2007 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/j.bbrc.2007.07.190· OSTI ID:21032929

Yoshida, Mariko ^[1]; Hiromoto, Takeshi ^[2]; Hosokawa, Keiichi ^[3]; Yamaguchi, Hiroshi ^[4]; Fujiwara, Shinsuke ^[1]

---

1. Department of Bioscience, Nanobiotechnology Research Center, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)
2. Research Center for Near Infrared Spectroscopy, Graduate School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)
3. Proteomics Research Laboratory, 1-16-1 Amakubo, Tsukuba, Ibaraki 300-0005 (Japan)
4. Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)

MobR from Comamonas testosteroni KH122-3s is a member of the MarR family of transcriptional regulators and functions as a repressor for the mobA gene that encodes a 3-hydroxybenzoate 4-hydroxylase. 3-Hydroxybenzoate binds to MobR as a ligand, resulting in an efficient induction of mobA. Various 3-hydroxybenzoate analogues were examined for their inducibilities using the mobA::lacZ transcriptional fusion system. {beta}-Galactosidase was induced by the addition of 2,3-dihydroxybenzoate or 3,5-dihydroxybenzoate besides 3-hydroxybenzoate, suggesting that the hydroxyl group at position 3 is critical in addition to the carboxyl group on the aromatic ring. A gel mobility-shift assay also showed that MobR was released from the target DNA in the presence of these compounds. Circular dichroism studies demonstrated that MobR adopted two conformational states corresponding to the 3-hydroxybenzoate-bound and unbound forms. Other ligands also induced the structural change as well; however, the tertiary structures of converted forms were different from those by 3-hydroxybenzoate.

• OSTI ID: 21032929
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 2 Vol. 362; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
DICHROISM
DNA
GALACTOSIDASE
GELS
GENES
HYDROXIDES
HYDROXYLASES
LIGANDS
SPECIFICITY
ULTRAVIOLET RADIATION