Talk:Sigma factor

Sigma number?

What is the 'sigma' in sigma factor? Why the different numbers? (i.e. what is the naming convention based on?) It does not appear to be based on molecular weight as with the heat shock proteins (because sigma 70 is about 40 kDa, at least in the PDB). Is it a parameter based on ultracentrifugation? Thanks for any insight. --Dan|^(talk) 16:37, 30 June 2006 (UTC)

Sigma 70 is 70kDA in E.coli

This is indeed strange in PDB; for example http://www.rcsb.org/pdb/explore.do?structureId=1SIG shows about 40 kDa. But all textbooks I know, refer to sigma-70 as the name was given to indicate its molecular weight. So I can understand the confusion by Dan above. 2A02:8388:1603:CB00:3AD5:47FF:FE18:CC7F (talk) 19:28, 25 September 2017 (UTC)

Merge proposal

Regarding the proposal to merge with Sigma protein and Sigma subunit by Tameeria:

Support "Sigma protein" is completely redundant with this article and should not exist; "Sigma subunit" makes no sense without the background provided by this article. Both articles should be redirects to this page. Adrian J. Hunter^{(talk•contribs)} 11:44, 9 December 2007 (UTC)

Support What Adrian says. Spitshine (talk) 11:47, 3 March 2008 (UTC)

Merged by redirecting sigma protein and sigma subunit to sigma factor. – ClockworkSoul 16:42, 21 March 2008 (UTC)

link

The "initiation factor" link at the beginning of this article directs to a description of translation, rather than transcription, initiation factors. —Preceding unsigned comment added by 129.137.226.9 (talk) 17:50, 22 July 2009 (UTC)

Thanks for the tip. I've fixed it by delinking initiation factor and linking "transcription" to Transcription (genetics). Adrian J. Hunter^{(talk•contribs)} 11:19, 23 July 2009 (UTC)

Merge proposal: Specificity factor

Should Specificity factor be merged into this article? I'll post further queries to appropriate people when I get the time - I just got back from vacation (if someone else wishes to do so, feel free!). Allens (talk) 02:05, 4 January 2012 (UTC)

Source?

"The sigma factor in the RNA polymerase holoenzyme complex is required for the initiation of transcription, although once that stage is finished, it is dissociated from the complex and the RNAP continues elongation on its own." to whoever wrote this: what is your source? I would like to use that source in an article of mine. Kayleighvandongen (talk) 12:22, 11 September 2025 (UTC)

could this be a source? https://doi.org/10.1016/j.molcel.2005.10.011 Kayleighvandongen (talk) 12:40, 11 September 2025 (UTC)