3.1.21.1	deoxyribonuclease I	-	
3.1.21.10	crossover junction endodeoxyribonuclease	-	
3.1.21.2	deoxyribonuclease IV	-	
3.1.21.3	type I site-specific deoxyribonuclease	-	
3.1.21.4	type II site-specific deoxyribonuclease	-	
3.1.21.5	type III site-specific deoxyribonuclease	-	
3.1.21.6	CC-preferring endodeoxyribonuclease	-	
3.1.21.7	deoxyribonuclease V	-	
3.1.21.8	T4 deoxyribonuclease II	-	
3.1.21.9	T4 deoxyribonuclease IV	-	
3.1.21.B1	endonuclease Q	preliminary BRENDA-supplied EC number	
3.1.21.B2	restriction endonuclease PabI	preliminary BRENDA-supplied EC number	
3.1.21.B3	mismatch-specific endonuclease	preliminary BRENDA-supplied EC number