AlkB protein active site. Computer illustration showing the molecular structure of the active site of an E. coli (Escherichia coli) AlkB protein. AlkB protein is a direct dealkylation DNA repair protein. AlkB is involved in DNA (deoxyribonucleic acid) repair and is induced during an adaptive response - a form of direct DNA repair in E. coli that protects DNA from damage by external agents or by errors during replication. It is involved in the direct reversal of alkylation damage to single stranded (SS) DNA caused by SN2 type chemical agents, where it removes methyl groups from 1-methyl adenines and 3-methyl cytosines in SS DNA.