Recruited co-dependently with zhp-2 to the synaptonemal complex between homologous chromosome pairs to regulate the formation and number of crossover events between homologs during meiotic recombination (PubMed:29521627). Together with zhp-2, promotes the accumulation of pro-crossover proteins, including zhp-3 and zhp-4, at a designated crossover site along the recombination intermediate (PubMed:29521627). Limits the number of crossover sites along a recombination intermediate by restricting the association of these pro-crossover proteins with other recombination sites during late prophase (PubMed:29521627). Also, together with zhp-2, plays a role in chromosome remodeling following crossover formation to promote two successive rounds of chromosome segregation during meiosis (PubMed:29521627). Interacts with zhp-2; the interaction is required for their chromosome association and stability. In association with zhp-2, localizes to chromosomes from pachytene to early diakinesis in the germ line (PubMed:29521627). Co-localizes with syp-1, a component of the synaptonemal complex from early prophase to mid-pachytene (PubMed:29521627). From mid-pachytene to diplotene, co-localizes with syp-1 on one side of each crossover site (PubMed:29521627). Remains co-localized with syp-1 along the short arm of homologous chromosomes through to late diakinesis (PubMed:29521627). At late pachytene, localization at chromosomes is not dependent on syp-1 (PubMed:29521627). Expressed in the germline.