A structure-specific endonuclease that resolves Holliday junction (HJ) intermediates during genetic recombination; may have some degree of sequence preference in a mobile junction. Cleaves 4-way DNA junctions introducing paired nicks in opposing strands, leaving a 5'-terminal phosphate and a 3'-terminal hydroxyl group that are ligated to produce recombinant products. Can cleave all 4 strands 3 bases 3' of the junction center. Cleaves both mobile and immobile junctions. Modifies the structure of the 4-way DNA junction, a model Holliday junction structure. The protein forms multiple complexes with 4-way DNA, suggesting more than 1 homodimer can bind to each junction. Endonucleolytic cleavage at a junction such as a reciprocal single-stranded crossover between two homologous DNA duplexes (Holliday junction). Binds 1 Mg(2+) ion per subunit. Autoinhibits at very high concentrations, possibly because of extreme junction distortion. Inhibition (and activity at low concentrations of enzyme) is stimulated by dsDNA and Sso7d (PubMed:11709558). Activity stimulated by PCNA subunit PCNA1 (PubMed:17011573). Homodimer (Probable). Interacts with PCNA subunit PCNA1. A second Holliday junction resolving enzyme, Hje, with different substrate specificity exists in this organism. Belongs to the Holliday junction resolvase Hjc family.