RRC ID 4932
Author Rankin LD, Bodenmiller DM, Partridge JD, Nishino SF, Spain JC, Spiro S.
Title Escherichia coli NsrR regulates a pathway for the oxidation of 3-nitrotyramine to 4-hydroxy-3-nitrophenylacetate.
Journal J Bacteriol
Abstract Chromatin immunoprecipitation and microarray (ChIP-chip) analysis showed that the nitric oxide (NO)-sensitive repressor NsrR from Escherichia coli binds in vivo to the promoters of the tynA and feaB genes. These genes encode the first two enzymes of a pathway that is required for the catabolism of phenylethylamine (PEA) and its hydroxylated derivatives tyramine and dopamine. Deletion of nsrR caused small increases in the activities of the tynA and feaB promoters in cultures grown on PEA. Overexpression of nsrR severely retarded growth on PEA and caused a marked repression of the tynA and feaB promoters. Both the growth defect and the promoter repression were reversed in the presence of a source of NO. These results are consistent with NsrR mediating repression of the tynA and feaB genes by binding (in an NO-sensitive fashion) to the sites identified by ChIP-chip. E. coli was shown to use 3-nitrotyramine as a nitrogen source for growth, conditions which partially induce the tynA and feaB promoters. Mutation of tynA (but not feaB) prevented growth on 3-nitrotyramine. Growth yields, mutant phenotypes, and analyses of culture supernatants suggested that 3-nitrotyramine is oxidized to 4-hydroxy-3-nitrophenylacetate, with growth occurring at the expense of the amino group of 3-nitrotyramine. Accordingly, enzyme assays showed that 3-nitrotyramine and its oxidation product (4-hydroxy-3-nitrophenylacetaldehyde) could be oxidized by the enzymes encoded by tynA and feaB, respectively. The results suggest that an additional physiological role of the PEA catabolic pathway is to metabolize nitroaromatic compounds that may accumulate in cells exposed to NO.
Volume 190(18)
Pages 6170-7
Published 2008-9-1
DOI 10.1128/JB.00508-08
PII JB.00508-08
PMID 18658270
PMC PMC2546798
MeSH DNA-Binding Proteins / genetics DNA-Binding Proteins / metabolism* Escherichia coli / genetics Escherichia coli / growth & development Escherichia coli / metabolism* Escherichia coli Proteins / genetics Escherichia coli Proteins / metabolism* Gene Expression Regulation, Bacterial* Nitric Oxide / metabolism Nitric Oxide / pharmacology Nitrophenols / metabolism* Oxidation-Reduction Phenethylamines / metabolism Phenylacetates / metabolism* Promoter Regions, Genetic / drug effects Transcription Factors / genetics Transcription Factors / metabolism* Tyramine / analogs & derivatives* Tyramine / metabolism
IF 3.234
Times Cited 26
Prokaryotes E. coli ME7986(MG1655) JW1379 pRS415