A Portrait of RNA Polymerase

What am I looking at?

This is a 3D rendering of an RNA polymerase II enzyme from baker’s yeast, created using actual molecular data to reconstruct its shape and active sites. What looks like a multicolored cloud is the 10 subunits of the enzyme shown in different colors (1). The blue, yellow, and red double-stranded helix is a representation of a strand of DNA that the enzyme is transcribing into RNA (2). The newly created RNA is pink and purple (3). You can also see the molecular structure of an adenosine triphosphate (ATP) molecule in orange, below the RNA (4).

Biology in the background

Enzymes called RNA polymerases transcribe DNA into RNA. RNA is the intermediary that carries the information contained within DNA to the ribosomes, where the genetic information is synthesized into proteins.

There are a variety of different types of RNA polymerases that can transcribe different types of RNA. RNA polymerase II, shown here, is responsible for creating messenger RNA (mRNA), which is the main type of RNA that gets translated into proteins. It can also create a few other types of RNA, including small nuclear RNA (which forms complexes with other proteins to process mRNA) and microRNA (which regulates the translation process).

An RNA polymerase II molecule is about 15 nanometers across, or roughly 5,000 times smaller than the width of a human hair.

Technique

This image was created by reconstructing X-ray diffraction crystallography data into a 3D representation of the structure of this enzyme.