@article{LavyshSokolovaSlashchevaetal.2017, author = {Lavysh, Daria and Sokolova, Maria and Slashcheva, Marina and F{\"o}rstner, Konrad U. and Severinov, Konstantin}, title = {Transcription profiling of "bacillus subtilis" cells infected with AR9, a giant phage encoding two multisubunit RNA polymerases}, series = {mBio}, volume = {8}, journal = {mBio}, number = {1}, doi = {10.1128/mBio.02041-16}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-181810}, year = {2017}, abstract = {Bacteriophage AR9 is a recently sequenced jumbo phage that encodes two multisubunit RNA polymerases. Here we investigated the AR9 transcription strategy and the effect of AR9 infection on the transcription of its host, Bacillus subtilis. Analysis of whole-genome transcription revealed early, late, and continuously expressed AR9 genes. Alignment of sequences upstream of the 5′ ends of AR9 transcripts revealed consensus sequences that define early and late phage promoters. Continuously expressed AR9 genes have both early and late promoters in front of them. Early AR9 transcription is independent of protein synthesis and must be determined by virion RNA polymerase injected together with viral DNA. During infection, the overall amount of host mRNAs is significantly decreased. Analysis of relative amounts of host transcripts revealed notable differences in the levels of some mRNAs. The physiological significance of up- or downregulation of host genes for AR9 phage infection remains to be established. AR9 infection is significantly affected by rifampin, an inhibitor of host RNA polymerase transcription. The effect is likely caused by the antibiotic-induced killing of host cells, while phage genome transcription is solely performed by viral RNA polymerases.}, language = {en} } @article{ZukherNovikovaTikhonovetal.2014, author = {Zukher, Inna and Novikova, Maria and Tikhonov, Anton and Nesterchuk, Mikhail V. and Osterman, Ilya A. and Djordjevic, Marko and Sergiev, Petr V. and Sharma, Cynthia M. and Severinov, Konstantin}, title = {Ribosome-controlled transcription termination is essential for the production of antibiotic microcin C}, series = {Nucleic Acids Research}, volume = {42}, journal = {Nucleic Acids Research}, number = {19}, issn = {0305-1048}, doi = {10.1093/nar/gku880}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-114839}, pages = {11891-11902}, year = {2014}, abstract = {Microcin C (McC) is a peptide-nucleotide antibiotic produced by Escherichia coli cells harboring a plasmid-borne operon mccABCDE. The heptapeptide MccA is converted into McC by adenylation catalyzed by the MccB enzyme. Since MccA is a substrate for MccB, a mechanism that regulates the MccA/MccB ratio likely exists. Here, we show that transcription from a promoter located upstream of mccA directs the synthesis of two transcripts: a short highly abundant transcript containing the mccA ORF and a longer minor transcript containing mccA and downstream ORFs. The short transcript is generated when RNA polymerase terminates transcription at an intrinsic terminator located in the intergenic region between the mccA and mccB genes. The function of this terminator is strongly attenuated by upstream mcc sequences. Attenuation is relieved and transcription termination is induced when ribosome binds to the mccA ORF. Ribosome binding also makes the mccA RNA exceptionally stable. Together, these two effects-ribosome induced transcription termination and stabilization of the message-account for very high abundance of the mccA transcript that is essential for McC production. The general scheme appears to be evolutionary conserved as ribosome-induced transcription termination also occurs in a homologous operon from Helicobacter pylori.}, language = {en} }