Structural highlights
Function
[RPOL_BPT7] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Responsible for the transcription of the late genes of T7. It is rifampicin-resistant. It recognizes a specific promoter sequence, unwinds the double-stranded RNA to expose the coding strand for templating, initiates transcription preferentially with a purine. [ENLYS_BPT7] Plays an important role in the switch between viral transcription and T7 genome replication. Once produced in sufficient amount, interacts with and inhibits T7 RNA polymerase that becomes unable to produce additional transcripts. This lysozyme-polymerase complex in turn plays an active role in T7 genome replication and packaging. Endolysin with amidase activity that degrades host peptidoglycans and participates with the holin and spanin proteins in the sequential events which lead to the programmed host cell lysis releasing the mature viral particles. Once the holin has permeabilized the host cell membrane, the endolysin can reach the periplasm and breaking down the peptidoglycan layer.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The T7 RNA polymerase-T7 lysozyme complex regulates phage gene expression during infection of Escherichia coli. The 2.8 A crystal structure of the complex reveals that lysozyme binds at a site remote from the polymerase active site, suggesting an indirect mechanism of inhibition. Comparison of the T7 RNA polymerase structure with that of the homologous pol I family of DNA polymerases reveals identities in the catalytic site but also differences specific to RNA polymerase function. The structure of T7 RNA polymerase presented here differs significantly from a previously published structure. Sequence similarities between phage RNA polymerases and those from mitochondria and chloroplasts, when interpreted in the context of our revised model of T7 RNA polymerase, suggest a conserved fold.
Structure of T7 RNA polymerase complexed to the transcriptional inhibitor T7 lysozyme.,Jeruzalmi D, Steitz TA EMBO J. 1998 Jul 15;17(14):4101-13. PMID:9670025[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Jeruzalmi D, Steitz TA. Structure of T7 RNA polymerase complexed to the transcriptional inhibitor T7 lysozyme. EMBO J. 1998 Jul 15;17(14):4101-13. PMID:9670025 doi:10.1093/emboj/17.14.4101
