Editing Lambda phage (section)

====Q antitermination====
{{multiple image
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|footer =  The Q protein modifies the RNA polymerase at the promoter region and is  recruited to RNA polymerase. The Q protein turns into a RNA polymerase subunit after it is recruitment to RNAP and modifies the enzyme into a processive state.  Note that NusA can stimulate the activity of the Q protein.<ref name="Korlach 2008">{{cite journal | vauthors = Santangelo TJ, Artsimovitch I | title = Termination and antitermination: RNA polymerase runs a stop sign | journal = Nature Reviews. Microbiology | volume = 9 | issue = 5 | pages = 319–329 | date = May 2011 | pmid = 21478900 | pmc = 3125153 | doi = 10.1038/nrmicro2560 }}</ref>

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| alt1      = Step 1

|image2 = QantiterminationSupplement.jpg

| image3    = Qantitermination2.jpg
| alt3      = Step 2
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Q is similar to N in its effect: Q binds to [[RNA polymerase]] in ''Qut'' sites and the resulting complex can ignore terminators, however the mechanism is very different; the Q protein first associates with a DNA sequence rather than an mRNA sequence.<ref name="Deighan, P. and Hochschild, A.">{{cite journal | vauthors = Deighan P, Hochschild A | title = The bacteriophage lambdaQ anti-terminator protein regulates late gene expression as a stable component of the transcription elongation complex | journal = Molecular Microbiology | volume = 63 | issue = 3 | pages = 911–920 | date = February 2007 | pmid = 17302807 | doi = 10.1111/j.1365-2958.2006.05563.x | doi-access = free }}</ref>
# The ''Qut'' site is very close to the ''P<sub>R’</sub>'' promoter, close enough that the σ factor has not been released from the RNA polymerase holoenzyme. Part of the ''Qut'' site resembles the -10 [[Pribnow box]], causing the holoenzyme to pause.
# Q protein then binds and displaces part of the σ factor and transcription re-initiates.
# The head and tail genes are transcribed and the corresponding proteins self-assemble.