Identification of an AraC-like regulator gene required for induction of the 78-kDa ferrioxamine B receptor in Vibrio vulnificus.
We previously reported that the 78-kDa outer membrane receptor for ferrioxamine B is induced in iron-starved Vibrio vulnificus cells when desferrioxamine B was supplied exogenously. Based on its N-terminal amino acid sequence, a candidate gene for the ferrichrome B receptor was detected in the V. vulnificus CMCP6 genomic database. Here, two contiguous genes, named desR and desA, encoding a member of the AraC family of transcriptional activators and the ferrioxamine B receptor, respectively, were cloned from V. vulnificus M2799 and characterized. Primer extension analysis mapped the iron-regulated transcription initiation sites for desR and desA, and demonstrated involvement of desferrioxamine B in the induction of desA transcription. Insertion mutation of desR resulted in no production of DesA under iron-limiting conditions even in the presence of desferrioxamine B. The DesA production under the same conditions was restored to wild-type levels when the desR mutant was complemented with desR in trans. These results suggest that the desR gene is required for desferrioxamine B-inducible production of DesA in iron-starved cells.
Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan.
Tomotaka
T
Tanabe
Noriko
N
Takata
Ayaka
A
Naka
Yong-Hwa
YH
Moon
Hiroshi
H
Nakao
Yuji
Y
Inoue
Shizuo
S
Narimatsu
Shigeo
S
Yamamoto
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001483:Base Sequence; D003561:Cytarabine; D017931:DNA Primers; D030561:Databases, Nucleic Acid; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D010641:Phenotype; D011956:Receptors, Cell Surface / Q000235:genetics*; D015183:Restriction Mapping; D013728:Terminator Regions, Genetic / Q000235:genetics; D041261:Vibrio vulnificus / Q000235:genetics*
D001425:Bacterial Outer Membrane Proteins; D017931:DNA Primers; C489524:FoxA protein, bacteria; D011956:Receptors, Cell Surface; D003561:Cytarabine