期刊
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
卷 79, 期 21, 页码 6730-6736出版社
AMER SOC MICROBIOLOGY
DOI: 10.1128/AEM.01804-13
关键词
-
资金
- CLIB-Graduate Cluster Industrial Biotechnology
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 assayed for consequences of extracellular sulfur supply and observed a graded fluorescence increase at decreasing sulfur concentrations below 400 mu M. Overall, this demonstrates the usefulness of the sensors for monitoring intracellular sulfur availability. The sensors also enable monitoring at the single-cell level, and since related and close homologs of the transcription factor used in the constructed sensors are widespread among bacteria, this technology offers a new possibility of assaying in vivo for sulfur limitation and of doing this at the single-cell level.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据