Maining his operons we performed real-time RT-PCR analysis of C. glutamicum ATCC 13032 grown on minimal medium without having and with 1 mM histidine supplementation.2013 The Authors. Microbial Biotechnology published by John Wiley Sons Ltd and Society for Applied Microbiology, Microbial Biotechnology, 7, 5Histidine in C. glutamicum Surprisingly, these experiments did not reveal any differences in transcription of his genes, neither organized in the hisDCB-cg2302-cg2301 operon nor inside the 3 remaining operons (data not shown). The same holds correct for any histidine dipeptide addition experiment analysed via subsequent real-time RT-PCR and micro-array evaluation. No differences in transcription of his genes have been observed immediately after addition in the dipeptide, suggesting that, in contrast to C. glutamicum AS019, histidine will not affect transcription of the his genes in C. glutamicum ATCC 13032 (information not shown). The inconsistent results for the two C. glutamicum strains can’t be explained so far. Although the DNA-sequence upstream of the hisD seems to be identical in each C.Gentamicin sulfate glutamicum strains, it cannot the excluded fully that transcription of his genes is regulated differently in these two strains in respect for the effect of histidine. Strain-specific variations are currently clear inside the distinctive transcription start web sites in front in the hisD genes in each organisms resulting in 5 UTRs of various length. The hisD leader sequence in C. glutamicum ATCC 13032 is a great deal shorter and consists of only 93 nt (R.Streptomycin K.PMID:24423657 Kulis-Horn, unpubl. obs.). Whereas the longer hisD five UTR from C. glutamicum AS019 is clearly involved in transcriptional regulation, we suggest a translational handle mechanism for the shorter hisD five UTR from C. glutamicum ATCC 13032, which will be discussed in detail below. Translational regulation The translation process is part of the attenuation mechanism regulating transcription of his genes in E. coli and S. typhimurium (see above). Besides this, there is no report that translation from the his operon is regulated once the full mRNA is transcribed in these two organisms. However, there is proof for any translational regulation mechanism in C. glutamicum. Jung and colleagues (2010) identified a 196 nt extended five UTR in front with the hisDCB-orf1-orf2 operon in C. glutamicum AS019 which can fold into two option secondary structures, one of them sequestering the SD sequence in a hair pin (see above). Though Jung and colleagues (2010) demonstrated that this T-box like RNA-element impacts transcription of the hisDCB-orf1-orf2 operon, the possibility of an added translational handle by this procedure remains. T-box RNAs are usually known to regulate transcription only (Gutierrez-Preciado et al., 2009). Nevertheless, a comparative evaluation of RNA regulatory components of amino acid metabolism genes from many bacteria revelled that some T-boxes from Actinobacteria could be involved in regulation of translation initiation alternatively (Seliverstov et al., 2005). The T-box RNA identified in front on the ileS gene of C. glutamicum for example sequesters the SD sequence in the alternative hairpin alternatively offorming a transcriptional terminator (Seliverstov et al., 2005). But, the bioinformatics analysis performed by Seliverstov et al. did not determine related regulatory RNA components in front of your his genes in C. glutamicum or other Actinobacteria. This could be attributed to the reality that translation-regulating T-boxes of Actinobacteria have a.
