Visualization of imbalances in sulfur assimilation and synthesis of sulfur-containing amino acids at the single-cell level.

ABSTRACT: We describe genetically encoded sensors which transmit elevated cytosolic concentrations of O-acetyl serine (OAS) and O-acetyl homoserine (OAH)-intermediates of l-cysteine and l-methionine synthesis-into an optical output. The sensor pSenOAS3 elicits 7.5-fold-increased fluorescence in cultures of a Corynebacterium glutamicum strain that excrete l-cysteine. Determination of the cytosolic OAS concentration revealed an increase to 0.13 mM, whereas the concentration in the reference strain was below the detection limit, indicating that incorporation of assimilatory sulfur is limited in the strain studied. In another strain, overexpression of metX encoding homoserine acetyltransferase resulted in an 8-fold increase in culture fluorescence at a cytosolic OAH concentration of 0.76 mM. We also ass

SUBMITTER: Hoffmann K 

PROVIDER: S-EPMC3811485 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature