. Author manuscript; available in PMC: 2013 Jan 22.

Published in final edited form as: Curr Gene Ther. 2012 Apr 1;12(2):77–91. doi: 10.2174/156652312800099571

Table 1.

Suicide Enzyme Information and Characteristics

Enzyme	Source-Gene	Subunit mass/Active form	Natural substrate	Prodrug	Variants/Mutants	Drug inhibitory action	References

Herpes Simplex Virus Thymidine Kinase (HSVTK)	Herpes Simplex Virus 1 (HSV-1) Thymidine Kinase (TK)	45kDa homodimer	Thymidine	GCV, ACV	Mutant 30	1	52, 56–60
					Mutant 75	1	52, 56, 58
					SR39	1	33, 58–65
					A168H	1	66
					A167Y	1	66, 69–72
					Q125N	1, 2	68, 71, 72

Bacterial Cytosine Deaminase (bCD)	Escherichia coli –codA	48kDa homohexamer	Cytosine	5-FC	D314 mutants	1, 2, 4	31, 34, 44, 74, 79
Bacterial Cytosine Deaminase (bCD)	Escherichia coli –codA	48kDa homohexamer	Cytosine	5-FC	bCD1525	1, 2, 4	31

Yeast Cytosine Deaminase (yCD)	Saccharomyces cerevisiae –fcy1	18kDa homodimer	Cytosine	5-FC	yCD triple	1, 2, 4	32, 81
Yeast Cytosine Deaminase (yCD)	Saccharomyces cerevisiae –fcy1	18kDa homodimer	Cytosine	5-FC	D92E	1, 2, 4	32

Drosophila melanogaster Deoxynucleoside Kinase (Dm-dNK)	Drosophilamelanogaster –dNK	29kDa hom	All four deo	AZT, ddC	MuD	1, 5	84–86
				CdA	B5	1	85, 87
				F-AraA	B10	1, 3	85
				GCV, AraG	M88R	1	87–90
				D4T	HDHD-12, HD-16	1, 5	91
				ddT	R4.V3	1	92

Deoxycytidine Kinase (dCK)	Homo sapiens –dCK	30.5kDa homodimer	Deoxycytidine	dFdC, AraC, L-dT	DM_MA, DM_LA	1, 3	100
				AZT	EpTK6	1, 3, 5	101
				dFdC, AraC	Ser-74	1, 3	102, 103

Purine Nucleoside Phosphorylase (PNP)	Escherichia coli -deoD	150kDa homodimer	Purine ribonucleosides	Me(talo)-MeP-R	M64V	1, 4	115, 117, 118

1. DNA synthesis

2. Thymidylate synthetase

3. Ribonucleotide reductase

4. RNA/protein synthesis

5. Reverse transcriptase