12 years ago, in my freshman year of high school (wow, I'm old!), I took my first true biology class. And in our text book was one image that enamored me to this squishy science. It showed the entire structure of DNA, from individual nucleic acids to an entire chromosome. In a single diagram it connected the theoretical world of atoms and molecules to the observable world of cells and chromosomes. I think it showed me that, with enough study and a good enough microscope, I could someday explain everything around me. In that class I learned the genetic causes of my family's genetic disease and that through understanding the molecular mechanisms I could learn how to heal them. Though I wouldn't realize it for years, I had started down the road to a career in medicine.
TIL: That image from all those years ago has become clearer in the intervening time. We knew that the DNA double helix was wrapped around histone proteins and that these bundles formed helices of their own. Further we knew that proteins called cohesins and condensins seemed important in the higher-order folding of chromatin into a structured chromosome, but we didn't understand exactly how. Now we know (mostly)!
Both condensin and cohesin are ringed proteins composed of SMC subunits. These rings circle the DNA/histone coils and then link together forming rosettes (seen on the right). The rosettes loosely coil to form the superstructure of chromosomes.
Can't wait to see what the next dozen years brings!
TIL: That image from all those years ago has become clearer in the intervening time. We knew that the DNA double helix was wrapped around histone proteins and that these bundles formed helices of their own. Further we knew that proteins called cohesins and condensins seemed important in the higher-order folding of chromatin into a structured chromosome, but we didn't understand exactly how. Now we know (mostly)!
No comments:
Post a Comment