The Escherichia coli ssuEADCB gene cluster is required for the utilization of sulfur from aliphatic sulfonates and is regulated by the transcriptional activator Cbl.
The growth properties of an Escherichia coli strain carrying a chromosomal deletion of the ssuEADCB genes (formerly designated ycbPONME) indicated that the products of this gene cluster are required for the utilization of sulfur from aliphatic sulfonates. Sequence similarity searches indicated that the proteins encoded by ssuA, ssuB, and ssuC are likely to constitute an ABC type transport system, whereas ssuD and ssuE encode an FMNH(2)-dependent monooxygenase and an NAD(P)H-dependent FMN reductase, respectively (Eichhorn, E., van der Ploeg, J. R., and Leisinger, T. (1999) J. Biol. Chem. 274, 26639-26646). Synthesis of beta-galactosidase from a transcriptional chromosomal ssuE'-lacZ fusion was repressed by sulfate or cystine and depended on the presence of a functional cbl gene, which encodes a LysR-type transcriptional regulator. Electrophoretic mobility shift assays with the ssu promoter region and measurements of beta-galactosidase from plasmid-encoded ssuE'-'lacZ fusions showed that full expression of the ssu operon required the presence of a Cbl-binding site upstream of the -35 region. CysB, the LysR transcriptional regulator for the cys genes, was not required for expression of a chromosomal ssuE'-lacZ fusion although the ssu promoter region contained three CysB-binding sites. Integration host factor could also occupy three binding sites in the ssu promoter region but had no influence on expression of a chromosomal ssuE'-lacZ fusion.
van Der Ploeg
J R
JR
Institut für Mikrobiologie, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich, Switzerland.
Iwanicka-Nowicka
R
R
Bykowski
T
T
Hryniewicz
M M
MM
Leisinger
T
T
D000476:Alkanesulfonates / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D034982:Integration Host Factors; D007763:Lac Operon; D008969:Molecular Sequence Data; D005810:Multigene Family; D009876:Operon; D010088:Oxidoreductases / Q000235:genetics; D010105:Oxygenases / Q000235:genetics; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins; D013455:Sulfur / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
D000476:Alkanesulfonates; D001426:Bacterial Proteins; C097229:Cbl protein, E coli; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D034982:Integration Host Factors; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D013455:Sulfur; D010088:Oxidoreductases; D010105:Oxygenases