DNA is tightly packed in the nucleus of every cell. DNA wraps around special proteins called histones, which form loops of DNA called nucleosomes. These nucleosomes coil and stack together to form fibers called chromatin. Chromatin in turn forms larger loops and coils to form chromosomes.
Once the structure of DNA was discovered, the next challenge was determining how the sequence of letters coded for the 20 amino acids. In theory, one or two letters can only code for 4 or 16 amino acids, respectively. A scheme using three letters, a triplet code, is the minimum necessary to...
The chromosome ends, or telomeres, are necessary for DNA stability and replication.
Single-molecule analysis using super-resolution microscopes reveals that transcription factors are not usually found bound to their binding sites on DNA.
Using super-resolution microscopes, scientists have uncovered how single protein molecules behave, and the results are astonishing.