TY - JOUR
T1 - Regulation of transcription of genes required for fatty acid transport and unsaturated fatty acid biosynthesis in Escherichiacoli by FadR
AU - DiRusso, Concetta O.
AU - Metzger, Amy K.
AU - Heimert, Tamra L.
PY - 1993/1
Y1 - 1993/1
N2 - Fatty acid biosynthesis and fatty acid degradation in Escherichiacoliare co‐ordinately regulated at the level of transcription by the product of the fadRgene, FadR. In the present work we investigate FadR interaction with the fabA and fadL promoters. The FadR‐responsive operator within fabA, OA, was localized to a region −47 to −31 base pairs relative to the start of transcription using DNase I protection studies. The promoter and untranslated leader within fadL had two binding sites for FadR, OL1 at −25 to −9 and OL2 at −1 to +16 relative to the start of transcription. The binding affinity of FadR for OA and OL1 or OL2 was lower than that for the single site within fadB (OB) as measured using protein‐DNA gel retention assays. Overall, these experiments demonstrated that the affinity of FadR binding for DNA containing the fadB, fadL and fabA promoters was OB > OL1, OL2 > OA. We could not distinguish separate binding affinities for OL1 or OL2. We demonstrated repression of fadL transcription and activation of fabA transcription in vitro using run‐off transcription assays containing purified FadR and RNA polymerase.
AB - Fatty acid biosynthesis and fatty acid degradation in Escherichiacoliare co‐ordinately regulated at the level of transcription by the product of the fadRgene, FadR. In the present work we investigate FadR interaction with the fabA and fadL promoters. The FadR‐responsive operator within fabA, OA, was localized to a region −47 to −31 base pairs relative to the start of transcription using DNase I protection studies. The promoter and untranslated leader within fadL had two binding sites for FadR, OL1 at −25 to −9 and OL2 at −1 to +16 relative to the start of transcription. The binding affinity of FadR for OA and OL1 or OL2 was lower than that for the single site within fadB (OB) as measured using protein‐DNA gel retention assays. Overall, these experiments demonstrated that the affinity of FadR binding for DNA containing the fadB, fadL and fabA promoters was OB > OL1, OL2 > OA. We could not distinguish separate binding affinities for OL1 or OL2. We demonstrated repression of fadL transcription and activation of fabA transcription in vitro using run‐off transcription assays containing purified FadR and RNA polymerase.
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U2 - 10.1111/j.1365-2958.1993.tb01122.x
DO - 10.1111/j.1365-2958.1993.tb01122.x
M3 - Article
C2 - 8446033
AN - SCOPUS:0027464211
VL - 7
SP - 311
EP - 322
JO - Molecular Microbiology
JF - Molecular Microbiology
SN - 0950-382X
IS - 2
ER -