The process of switching antibody class during B cell activation is extremely controlled and several enzymes participate in it. Below are listed th...

The process of switching antibody class during B cell activation is extremely controlled and several enzymes participate in it. Below are listed the events that occur during the molecular process of antibody class switching:


a. Activation-induced cytidine deaminase (AID) deaminates cytosine to uracil in the switch region of the heavy chain gene.
b. Uracil DNA glycosylase (UNG) removes uracil from DNA, creating an abasic site.
c. Apurinic/apyrimidinic endonuclease (APE) cleaves the DNA strand at the abasic site.
d. DNA polymerase eta (Pol η) fills in the gap by copying the sequence from the donor switch region.
e. All of the above.