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6p18
From Proteopedia
Revision as of 04:17, 11 April 2020 by OCA (Talk | contribs)
6p18 is a 11 chain structure with sequence from Bacteriophage 21 and Ecoli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
[RPOZ_ECOLI] Promotes RNA polymerase assembly. Latches the N- and C-terminal regions of the beta' subunit thereby facilitating its interaction with the beta and alpha subunits.[HAMAP-Rule:MF_00366] [RPOA_ECOLI] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. This subunit plays an important role in subunit assembly since its dimerization is the first step in the sequential assembly of subunits to form the holoenzyme.[HAMAP-Rule:MF_00059] [RPOD_ECOLI] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This is the primary sigma factor of this bacterium. [RPOB_ECOLI] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.[HAMAP-Rule:MF_01321] [RPOC_ECOLI] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.[HAMAP-Rule:MF_01322]
Publication Abstract from PubMed
Lambdoid bacteriophage Q protein mediates the switch from middle to late bacteriophage gene expression by enabling RNA polymerase (RNAP) to read through transcription terminators preceding bacteriophage late genes. Q loads onto RNAP engaged in promoter-proximal pausing at a Q binding element (QBE) and adjacent sigma-dependent pause element (SDPE) to yield a Q-loading complex, and Q subsequently translocates with RNAP as a pausing-deficient, termination-deficient Q-loaded complex. Here, we report high-resolution structures of 4 states on the pathway of antitermination by Q from bacteriophage 21 (Q21): Q21, the Q21-QBE complex, the Q21-loading complex, and the Q21-loaded complex. The results show that Q21 forms a torus, a "nozzle," that narrows and extends the RNAP RNA-exit channel, extruding topologically linked single-stranded RNA and preventing the formation of pause and terminator hairpins.
Structural basis of Q-dependent antitermination.,Yin Z, Kaelber JT, Ebright RH Proc Natl Acad Sci U S A. 2019 Sep 10;116(37):18384-18390. doi:, 10.1073/pnas.1909801116. Epub 2019 Aug 27. PMID:31455742[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
