What is the Difference Between Ferredoxin and Rubredoxin?

Ferredoxin and rubredoxin are both iron-sulfur containing proteins involved in mediating electron transfer in various metabolic reactions. They share some similarities, but there are key differences between them:

1. Iron atoms: Rubredoxins contain a single iron atom bonded through four tetrahedrally arranged sulfur atoms to the rest of the protein. On the other hand, ferredoxins can have two iron atoms or four iron atoms.
2. Redox potential: The redox potential of ferredoxin is considerably lower than that of rubredoxin. The redox potential of ferredoxin is about -420 mV, while the reduction potential of rubredoxin ranges from +50 mV to -50 mV.
3. Electronic properties: The electronic properties of rubredoxin and ferredoxin differ due to the presence of multiple iron atoms in ferredoxin. This difference in electronic properties results from the magnetic coupling between the iron atoms in ferredoxin.

In summary, ferredoxin and rubredoxin are both iron-sulfur proteins involved in electron transfer, but they differ in the number of iron atoms they contain and their redox potentials.

Comparative Table: Ferredoxin vs Rubredoxin

Ferredoxin and rubredoxin are both iron-sulfur containing proteins involved in mediating electron transfer in various metabolic reactions. However, they have some differences, primarily in their redox potentials and structures. Here is a table comparing the two:

Ferredoxin has a considerably lower redox potential compared to rubredoxin. Ferredoxins can have two iron-sulfur clusters, while rubredoxins contain a single iron atom bonded through four tetrahedrally arranged sulfur atoms to the rest of the protein. Ferredoxins are found in chloroplasts, while rubredoxins are not.