Table 1.

Holliday junction resolvases

Organism	Enzyme	Oligomeric statea	Substrate specificityb	Junction conformationc	Sequence specificityd	Crystal structure
Eubacteria
Escherichia coli	RuvC	Homodimer	X	Open-X	A/TTT↓C>G/A	+
Archaea
Pyrococcus furiosus	Hjc	Homodimer	X	Open-X	No	+
Bacteriophage
Phage T4	T4 endo VII	Homodimer	X, Y, Z	Distorted open-X	Weak, T↓	+
Phage T7	T7 endo I	Homodimer	X, Y, Z	Coaxial stacked	Weak, C/T↓C/T	+
Eukaryotes
Saccharomyces cerevisiae	Cce1	Homodimer	X	Open square	ACT↓A	+
	Yen1	nd	X, Y, Z	nd	nd	−
	Mus81-Mms4	Heterodimer	X, Y, Z	nd	nd	−
	Slx1-Slx4	nd	X, Y, Z	nd	nd	−
Schizosaccharomyces pombe	Ydc2	Homodimer	X	Open square	C/TT↓	+
	Mus81-Eme1	nd	X, Y, Z	nd	nd	−
	Slx1-Slx4	nd	X, Y, Z	nd	nd	−
Homo sapiens	GEN1	Monomer	X, Y, Z	nd	nd	−
	MUS81-EME1	nd	X, Y, Z	nd	nd	+ (Chimera)
	SLX1-SLX4	nd	X, Y, Z	nd	nd	−

Survey of Holliday junction resolvases. Examples of the main classes of enzymes are tabulated. References are provided in the main text. nd, not determined.

^aOligomeric state as determined from crystal structures, electron microscopy, and/or analytical ultracentrifugation.

^bSubstrate specificity is defined as X for Holliday junctions, Y for three-way junctions, and Z for other branched substrates, such as 5′-flaps, 3′-flaps, or replication forks.

^cJunction conformation induced on protein binding, as deduced from biochemical studies, molecular modeling, and/or crystal structures.

^dDNA sequences written 5′ to 3′; cut site indicated by a vertical arrow.