Mutation analysis of the purine operon leader region in Bacillus subtilis

Reconstruction of Purine Metabolism in Bacillus subtilis to Obtain the Strain Producer of AICAR: A New Drug with a Wide Range of Therapeutic Applications

“…In work [ 21 ] devoted to the study of B. subtilis pur -operon expression, it was demonstrated that an almost 20-fold enhancement of the expression of the lacZ reporter gene integrated into the purH gene, as compared with the expression in the wild-type strain when the purR gene that encodes the repressor protein of the operon is damaged, is achieved. After deletion of 94 n.p.…”

“…The AM732-Pur + strain, a derivative of the earlier characterized Mu8u5u6 strain [ 21 ] ( Table 1 ), was used as starting material. In order to transfer the purR :: neo insertion, which completely inactivates the synthesis of the PurR repressor protein, into the genome of the АМ732 strain, this strain was transformed by chromosomal DNA isolated from the LCC28 ( purR :: neo) strain, with the selection of recombinants that were resistant to neomycin (Neo R ).…”

“…First, the long-stretched deletion ΔL-E was obtained, completely overlapping the leader region of the pur -operon and partially overlapping the first structural gene pur E, which resulted in the emergence of auxotrophicity with respect to purines. How to achieve this deletion was thoroughly described in [ 21 ]. The deletion of the transcription attenuator ΔT-purE was transferred into the AM743 purR :: neo ΔL-E strain by transforming DNA that was isolated from the AM747 strain ( Table 1 ); Pur + transformants were selected on the purine-free Spizizen’s minimal medium.…”

“…It was shown that PRPP acts as a low-molecular-weight effector of the PurR protein [ 15 ], whereas guanine serves as a modulator enhancing transcription termination prior to the first structural gene of the operon [ 17 ]. Later, it was revealed that a 5’-non-translatable sequence of mRNA has a sensory function with respect to the metabolite – guanine effector, and that it acts as the so-called riboswitch [ 18 , 19 ], providing early termination of operon transcription [ 20 , 21 ].…”

Metabolic Engineering of Bacillus subtilis for Riboflavin Production: A Review

“…Deletion of the G-box in the purine operon mRNA leader region increased β-galactosidase activity by nearly 25-fold [ 38 ]. Lobanov et al knocked out the purR gene in B. subtilis AM732 and deleted the G-box, overexpressed the purine operon gene and increased the copy numbers of E. coli -derived purF on the chromosome, resulting in a yield of 13.0 g/L of 5-aminoimidazole-4-carboxamide ribonucleoside [ 39 , 40 ]. However, it was not applied to riboflavin synthesis and thus, its effect on yield was unclear.…”