The "last" gene, and also an E. Coli K-12 MG1655 gene of unknown function.
Since a matrix can be seen as a linear map , the product of two matrices can be seen as the composition of two linear maps:One cool thing about linear functions is that we can easily pre-calculate this product only once to obtain a new matrix, and so we don't have to do both multiplications separately each time.
Contains the genes: e. Coli K-12 MG1655 gene thrL, e. Coli K-12 MG1655 gene thrA, e. Coli K-12 MG1655 gene thrB and e. Coli K-12 MG1655 gene thrC, all of which have directly linked functionality.
We can find it by searching for the species in the BioCyc promoter database. This leads to: biocyc.org/group?id=:ALL-PROMOTERS&orgid=ECOLI.
That page lists several components of the promoter, which we should try to understand!
Some of the transcription factors are proteins:
After the first gene in the codon, thrL, there is a rho-independent termination. By comparing:we understand that the presence of threonine or isoleucine variants, L-threonyl and L-isoleucyl, makes the rho-independent termination become more efficient, so the control loop is quite direct! Not sure why it cares about isoleucine as well though.
Maybe the most famous one is Mycoplasma genitalium byt there are others, and notably with lower biosafety levels:
www.lgcstandards-atcc.org/products/all/49896.aspx:
- £355.00 in 2019
- biosafety level: 2
Reproduction time: www.quora.com/unanswered/How-long-do-Mycoplasma-bacteria-take-to-reproduce-under-optimal-conditions
Has one of the smallest genomes known, and JCVI made a minimized strain with 473 genes: JCVI-syn3.0.
The reason why genitalium has such a small genome is that parasites tend to have smaller DNAs. So it must be highlighted that genitalium can only survive in highly enriched environments, it can't even make its own amino acids, which it normally obtains fromthe host cells! And because it cannot do cellular respiration, it very likely replicates slower than say E. Coli. It's easy to be small in such scenarios!
Power, Sex, Suicide by Nick Lane (2006) section "How to lose the cell wall without dying" page 184 has some related mentions puts it well very:
One group, the Mycoplasma, comprises mostly parasites, many of which live inside other cells. Mycoplasma cells are tiny, with very small genomes. M. genitalium, discovered in 1981, has the smallest known genome of any bacterial cell, encoding fewer than genes. Despite its simplicity, it ranks among the most common of sexually transmitted diseases, producing symptoms similar to Chlamydia infection. It is so small (less than a third of a micron in diameter, or an order of magnitude smaller than most bacteria) that it must normally be viewed under the electron microscope; and difficulties culturing it meant its significance was not appreciated until the important advances in gene sequencing in the early 1990s. Like Rickettsia, Mycoplasma have lost virtually all the genes required for making nucleotides, amino acids, and so forth. Unlike Rickettsia, however, Mycoplasma have also lost all the genes for oxygen respiration, or indeed any other form of membrane respiration: they have no cytochromes, and so must rely on fermentation for energy.
Downsides mentioned at youtu.be/PSDd3oHj548?t=293:
- too small to see on light microscope
- difficult to genetically manipulate. TODO why?
- less literature than E. Coli.
Data:
- www.ncbi.nlm.nih.gov/bioproject/97 contains genome, genes, proteins.
- www.genome.jp/kegg-bin/show_pathway?mge01100 all known pathways. TODO: numerical reaction coefficients? Which enzyimes mediate what? Appears to factor pathways across organisms, which is awesome.
GPU accelerated, simulates the Craig's minimized M. genitalium, JCVI-syn3A at a particle basis of some kind.
Lab head is the cutest-looking lady ever: chemistry.illinois.edu/zan, Zaida (Zan) Luthey-Schulten.
- 2022 paper: www.cell.com/cell/fulltext/S0092-8674(21)01488-4 Fundamental behaviors emerge from simulations of a living minimal cell by Thornburg et al. (2022) published on Cell
- faculty.scs.illinois.edu/schulten/lm/ actual source code. No Version control and non-code drop release, openess and best practices haven't reached such far obscure reaches of academia yet. One day.
- blogs.nvidia.com/blog/2022/01/20/living-cell-simulation/ Nvidia announcement. That's how they do business, it is quite interesting how they highlight this kind of research.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 3. Visual Studio Code extension installation.
Figure 4. Visual Studio Code extension tree navigation.
Figure 5. Web editor. You can also edit articles on the Web editor without installing anything locally.Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.Video 4. OurBigBook Visual Studio Code extension editing and navigation demo. Source. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact