Band
3
Protein- The band 3 protein of Schnaitman (1974) was later shown to be composed of two different proteins, 3a and 3b. 3a is identical to the to lG protein.
This is a heat-modifiable and trypsin-sensitive protein which is absent in to1 G mutants.
Like the matrix proteins, to lG protein also has a high β structure content.
It appears to be exposed to the outer surface of the membrane, and serves as a receptor for certain phages.
It has an important function in F-pilus mediated conjugation.
