In this article we will discuss about the role of RNA polymerase in transcription. RNA polymerase enzymes are complex enzyme which in E. coli is made up of 5 subunits or polypeptide chains designated β, β', α, σ and ω with respective molecular weights of 160,000, 150,000, 90,000, 40,000 and 10,000. The α chain is present twice, others only once. [...]
Ribosomes involved in protein synthesis could lie free in the cytoplasm or are bound to membranes of endoplasmic reticulum. Free ribosomes synthesise protein without a signal sequence, and continue synthesis until the polypeptide is completed. Such a protein may assume its three-dimensional conformation with the help of chaperones present in the cytosol. Some of the important destinations for proteins synthesised [...]
The reconstitution of ribosomes has been a dramatic advance of recent times. When ribosomes are centrifuged in a gradient of 5M CsCl, about 30 to 40% of the protein is lost. Both the subunits dissociated into 2 inactive core particles which contain the RNA and some proteins (core proteins). Simultaneously some other proteins called split proteins (SP) are released from [...]