Effect of FarR on transcriptional levels of arginine biosynthetic genes in Corynebacterium crenatum AS 1.542 and its relationship with ArgR

Abstract:

Abstract:［Objective］ The FarR protein was involved in the regulation of arginine biosynthetic pathway in corynebacterium，but the regulation mechanism of FarR protein and its relationship with the negative regulator ArgR have never been reported．In this work，we constructed two deletion mutants: C． crenatum △farR and C．crenatum △argR △farR，and investigated the FarR function and its relationship with ArgR through the determination of transcriptional levels of arginine biosynthetic genes in four strains，including C．crenatum △argR constructed in previous work.［Methods］We used marker-less knockout technology to construct C．crenatum △farR and C．crenatum △argR△farR，and compared the transcriptional levels of the arginine biosynthetic genes in three mutant strains with those of the wild type strain using real-time fluorescence quantitative PCR.［Ｒesults］The results of ＲT-qPCR indicate that，in the absence of ArgR，FarR acted as a positive regulator．When farR gene was knockout alone，the transcriptional levels of arginine biosynthetic genes appeared up-regulated，down-regulated or no influence．［Conclusion］FarR and ArgＲ are involved together in the regulation of arginine biosynthetic pathway of C．crenatum．