Ubiquitin E3 ligase required for class I crossover (CO) formation during meiosis. S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine. Protein modification; protein ubiquitination. Interacts with ZIP4 and PTD. Dynamic localization on the meiotic chromosomes. Initially appears as distinct foci. Later observed along the chromosomes and finally restrict to prominent foci that specially localize to chiasma sites. Extends along the chromosome in the wake of synapsis. Expressed in young panicles. The mutants hei10-1 and hei10-2 have normal vegetative growth but exhibited complete sterility, due to shrunken and inviable pollen as well as sterile female gametes. Reduced chiasma frequency, with a random distribution among cells of remaining chiasmata, but normal early recombination events and synaptonemal complex (SC) formation.