Talk:Type VII secretion system

Wiki Education assignment: MICR 4054

This article was the subject of a Wiki Education Foundation-supported course assignment, between 30 August 2022 and 16 December 2022. Further details are available on the course page. Student editor(s): Dabbsarah19, Abri.paez!, PreoccupiedWarlock, Sparkly Amoeba (article contribs).

— Assignment last updated by QueenStarrUniverse (talk) 20:05, 29 September 2022 (UTC)

Completeness

There are two systems that have been called a Type VII secretion system: one in mycobacteria and one in gram-negative bacteria (chaperone-usher fimbriae). Be sure to discuss both in the article. Ninjatacoshell (talk) 19:21, 10 October 2022 (UTC)

Some thoughts

There are some issues with this article- it mixes up the different type VII secretion systems in Mycobacteria. I'll try to add open access citations, but some seminal papers may not be.

Generally speaking, there are five major T7SS in Mycobacteria, ESX-1-5. This is reviewed here:

https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1000507

ESX-1 mediates survival in macrophages and lysis. Sometimes the term RD1 is used to identify it as it was originally identified as a 'region of difference 1' when comparing the BCG live vaccine strain:

https://onlinelibrary.wiley.com/doi/full/10.1046/j.1365-2958.2002.03237.x

RD1 was named here if anyone is curious:

https://www.science.org/doi/10.1126/science.284.5419.1520

This is one of the first works that ties ESX-1 to lytic activity (and its importance in pathogenesis):

https://www.pnas.org/doi/10.1073/pnas.1635213100

In nonpathogenic bacteria (Mycobacteria smegmatis) there's some evidence it's involved in horizontal gene transfer along with ESX-4:

https://www.science.org/doi/10.1126/science.aag0828

ESX-2 is a bit of a mystery. As far as I know there's not a clear function for it.

ESX-3 is important for metal nutrient uptake which is crucial for the bug to survive during infection:

https://www.pnas.org/doi/10.1073/pnas.0900589106

https://www.pnas.org/doi/10.1073/pnas.1523321113

Famelis et al. (cited) is a structure of this system.

ESX-4 is involved in horizontal gene transfer as mentioned above.

ESX-5 is important for nutrient uptake and allowing pathogenic mycobacteria to have a highly impermeable membrane (important for surviving stress and antibiotics!). This was first observed in the pathogen Mycobacterium marinum:

https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1005190

then later confirmed in M. tuberculosis:

https://www.science.org/doi/10.1126/science.aav5912

This is the first structure of the ESX-5 secretory system (or any T7SS for that matter): https://www.nature.com/articles/nmicrobiol201747

Followed by these two high resoultion cryo em papers:

https://www.nature.com/articles/s41586-021-03517-z https://www.science.org/doi/full/10.1126/sciadv.abg9923

Hope this helps. — Preceding unsigned comment added by 95.147.176.60 (talk) 17:43, 16 November 2024 (UTC)