Regulation of flpA, flpB and rcfA promoters in Lactococcus lactis
Regulation of flpA, flpB and rcfA promoters in Lactococcus lactis
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DOI：
10.1007/s00284-008-9174-0
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发表时间：
2008-09-01
影响因子：
2.6
通讯作者：
Shearman, Claire A.
中科院分区：
文献类型：
--
作者：
Akyol, Ismail;Shearman, Claire A.
大肠杆菌富马酸硝酸还原酶 (FNR) 与保守的 FNR 位点结合，在厌氧条件下调节转录。乳酸乳球菌亚种cremoris MG1363 菌株含有由 flpA 和 flpB 基因编码的两种 FNR 样蛋白（FlpA 和 B），以及乳酸乳球菌亚种中由 rcfA 基因编码的 RcfA。乳酸IL1403菌株。潜在的 FNR 结合位点位于这些基因的上游。 flpA 启动子在 MG1363 中以厌氧和需氧方式表达。 flpB 和 rcfA 启动子具有典型的 II 类 FNR 依赖性启动子，分别在 MG1363 和 IL1403 中厌氧激活。尽管 Flp 和 RcfA 蛋白具有很强的同源性，但它们不能相互替代并控制异源菌株中的这些启动子。 flpA 和 flpB 启动子需要 FlpA 和 FlpB 在 MG1363 背景下激活。通过在 flp 突变体中在乳链菌肽控制下表达 FlpB 并监测 flpA 启动子表达，证实了这一点。在 flpB(-) 背景下，flpA 启动子表达需要 FlpA 和 FlpB。 FlpB 不能补充 flpA(-) 背景中 FlpA 蛋白的缺失。
E. coli fumarate nitrate reductase (FNR) binds to conserved FNR sites to regulate transcription under anaerobic condition. L. lactis subsp. cremoris MG1363 strain contains two FNR-like proteins (FlpA and B) encoded by flpA and flpB genes and the rcfA gene-encoded RcfA in L. lactis subsp. lactis IL1403 strain. Potential FNR-binding sites were located upstream of these genes. The flpA promoter is expressed in MG1363 anaerobically and aerobically. The flpB and rcfA promoters have typical class II FNR-dependent promoters and are activated anaerobically in MG1363 and IL1403, respectively. Despite their strong homology, the Flp and RcfA proteins cannot substitute for each other and control these promoters in the heterologous strains. The flpA and flpB promoters require FlpA and FlpB for activation in the MG1363 background. This was confirmed by expressing FlpB under nisin control in flp mutants and monitoring flpA promoter expression. In flpB(-) backgrounds, both FlpA and FlpB were required for flpA promoter expression. FlpB could not complement for the lack of FlpA protein in flpA(-) backgrounds.