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ArsR homolog YgaV autoregulates the theorized ygaV‐ygaP rhodanese operon in Escherichia coli
Author(s) -
Paul Katie Beth,
Larson Timothy J
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a70-a
Subject(s) - operon , rhodanese , biology , repressor , escherichia coli , lac operon , gene , transcription (linguistics) , genetics , gal operon , promoter , microbiology and biotechnology , biochemistry , transcription factor , gene expression , enzyme , linguistics , philosophy
The Escherichia coli genome is predicted to encode nine proteins with sequence similarity to rhodanese, an enzyme that catalyzes transfer of sulfur from thiosulfate to cyanide. The functions of YgaP, a membrane‐associated rhodanese, and previously characterized rhodaneses PspE and GlpE of E. coli, all remain unknown. The ygaV gene is located 10 base pairs upstream of ygaP , and is predicted to encode a protein of the ArsR family of prokaryotic transcriptional metalloregulators. This work determined that YgaV controls transcription of the presumptive ygaV‐ygaP operon. It was found that a ygaV‐lacZ transcriptional fusion was expressed at a level that was about 13 fold higher in a ygaV chromosomal deletion strain compared with its expression in a wild‐type strain, indicating that YgaV is a transcriptional repressor of its own promoter. This promoter region was localized to a 120 base pair region upstream of ygaV . The YgaV repressor was overexpressed and purified. Electrophoretic gel mobility shift assays revealed specific, high affinity binding of YgaV to the promoter region. Further research is aimed at localizing the operator within the promoter, identifying effectors that decrease the affinity of YgaV for its operator, as well as confirming the cotranscription of ygaV and ygaP . Elucidation of molecular details of regulation of the ygaV and ygaP operon by YgaV is expected to provide insight into the ultimate objective: to determine the physiological function of the operon to cellular sulfur metabolism. Funded by a grant from the Jeffress Memorial Trust.