Intragenic promoter adaptation and facilitated RNA polymerase III recycling in the transcription of SCR1, the 7SL RNA gene of Saccharomyces cerevisiae

The SCR1 gene, coding for the 7SL RNA of the signal recognition particle, is the last known class III gene of Saccharomyces cerevisiae that remains to be characterized with respect to its mode of transcription and promoter organization. We show here that SCR1 represents a unique case of a non-tRNA class III gene in which intragenic promoter elements (the TFIIIC-binding A- and B-blocks), corresponding to the D and TpsiC arms of mature tRNAs, have been adapted to a structurally different small RNA without losing their transcriptional function. In fact, despite the presence of an upstream canonical TATA box, SCR1 transcription strictly depends on the presence of functional, albeit quite unusual, A- and B-blocks and requires all the basal components of the RNA polymerase III transcription apparatus, including TFIIIC. Accordingly, TFIIIC was found to protect from DNase I digestion an 80-bp region comprising the A- and B-blocks. B-block inactivation completely compromised TFIIIC binding and transcription capacity in vitro and in vivo. An inactivating mutation in the A-block selectively affected TFIIIC binding to this promoter element but resulted in much more dramatic impairment of in vivo than in vitro transcription. Transcriptional competition and nucleosome disruption experiments showed that this stronger in vivo defect is due to a reduced ability of A-block-mutated SCR1 to compete with other genes for TFIIIC binding and to counteract the assembly of repressive chromatin structures through TFIIIC recruitment. A kinetic analysis further revealed that facilitated RNA polymerase III recycling, far from being restricted to typical small sized class III templates, also takes place on the 522-bp-long SCR1 gene, the longest known class III transcriptional unit

Consumer stated preferences for environmental labels: Two case studies in the dairy sector

No abstract availabl

Monumenti e materiali archeologici dell\u2019antico Piceno (Regio V)

Prosecuzione degli scavi nell'area urbana della colonia romana di Pollentia-Urbs Salvi

Transcriptional and post-transcriptional events trigger de novo infB expression in cold stressed Escherichia coli

After a 37 to 10°C temperature downshift the level of translation initiation factor IF2, like that of IF1 and IF3, increases at least 3-fold with respect to the ribosomes. To clarify the mechanisms and conditions leading to cold-stress induction of infB expression, the consequences of this temperature shift on infB (IF2) transcription, infB mRNA stability and translation were analysed. The Escherichia coli gene encoding IF2 is part of the metY-nusA-infB operon that contains three known promoters (P-1, P0 and P2) in addition to two promoters P3 and P4 identified in this study, the latter committed to the synthesis of a monocistronic mRNA encoding exclusively IF2. The results obtained indicate that the increased level of IF2 following cold stress depends on three mechanisms: (i) activation of all the promoters of the operon, P-1 being the most cold-responsive, as a likely consequence of the reduction of the ppGpp level that follows cold stress; (ii) a large increase in infB mRNA half-life and (iii) the cold-shock induced translational bias that ensures efficient translation of infB mRNA by the translational apparatus of cold shocked cells. A comparison of the mechanisms responsible for the cold shock induction of the three initiation factors is also presented

Roma ed il mondo adriatico: dalla ricerca archeologica alla pianificazione del territorio

Organizzazione del Convegno internazionale “Roma ed il mondo adriatico: dalla ricerca archeologica alla pianificazione del territorio” – Macerata 19-20 maggio 201

Roma ed il mondo adriatico: dalla ricerca archeologica alla pianificazione del territorio

Organizzazione del Convegno internazionale \u201cRoma ed il mondo adriatico: dalla ricerca archeologica alla pianificazione del territorio\u201d \u2013 Macerata 19-20 maggio 201

Althiburos (Tunisia). Scavo, studio e rilievo del teatro romano

La Missione dell'Universita' di Macerata, in collaborazione con l'Institut National du Patrimoine di Tunisi,ha come oggetto lo studio, il rilievo, lo scavo sistematico ed il progetto di restauro del Teatro romano di Althiburos (M'deina, nel Governatorato di El Kef). Vista la particolare situazione politica dell'area per il 2016 \ue8 stata effettuata una campagna di studio di materiali presso i magazzini archeologici di Cartagine

Althiburos (Tunisia). Scavo, studio e rilievo del teatro romano. L'architettura teatrale in Africa proconsolare

La Missione dell'Universita' di Macerata, in collaborazione con l'Institut National du Patrimoine di Tunisi, ha come oggetto lo studio, il rilievo, lo scavo ed il progetto di restauro del Teatro romano di Althiburos (Governatorato di El Kef). Per quest'anno si prevede di continuare la campagna di studio dei materiali gi\ue0 avviata nel 2016, di effettuare la messa in sicurezza dell'area scavo, una campagna di rilevamento del monumento con laser scanner 3D ed avviare il catalogo dei teatri tunisini