biostudies-literaturede Martin Garrido NRoyal SocietyWellcome Trust168713https://www.ebi.ac.uk/biostudies/studies/S-EPMC7618050biostudies-literatureUnknown436(18)Bacteriophage ΦKZ (PhiKZ) is the founding member of a family of giant bacterial viruses. It has potential as a therapeutic as its host, Pseudomonas aeruginosa, kills tens of thousands of people worldwide each year. ΦKZ infection is independent of the host transcriptional apparatus; the virus forms a "nucleus", producing a proteinaceous barrier around the ΦKZ genome that excludes the host immune systems. It expresses its own non-canonical multi-subunit non-virion RNA polymerase (nvRNAP), which is imported into its "nucleus" to transcribe viral genes. The ΦKZ nvRNAP is formed by four polypeptides representing homologues of the eubacterial β/β' subunits, and a fifth that is likely to have evolved from an ancestral homologue to σ-factor. We have resolved the structure of the ΦKZ nvRNAP initiatJournal of molecular biologyStructure of the Bacteriophage PhiKZ Non-virion RNA Polymerase Transcribing from its Promoter p119L.PMC7618050206212/Z/17/A206212206212/Z/17/ZYakunina Mde Martin Garrido NRamlaul KChen CSAylett CHSfalseStructure of the Bacteriophage PhiKZ Non-virion RNA Polymerase Transcribing from its Promoter p119L.Bacteriophage ΦKZ (PhiKZ) is the founding member of a family of giant bacterial viruses. It has potential as a therapeutic as its host, Pseudomonas aeruginosa, kills tens of thousands of people worldwide each year. ΦKZ infection is independent of the host transcriptional apparatus; the virus forms a "nucleus", producing a proteinaceous barrier around the ΦKZ genome that excludes the host immune systems. It expresses its own non-canonical multi-subunit non-virion RNA polymerase (nvRNAP), which is imported into its "nucleus" to transcribe viral genes. The ΦKZ nvRNAP is formed by four polypeptides representing homologues of the eubacterial β/β' subunits, and a fifth that is likely to have evolved from an ancestral homologue to σ-factor. We have resolved the structure of the ΦKZ nvRNAP initiat2024-01-01T00:00:00Z2024 Sep2026-06-06T00:29:35.11Z2026-05-24T03:11:38.305ZS-EPMC76180503902988810.1016/j.jmb.2024.168713