Calcium-binding peroxygenase involved in cutin monomers biosynthesis. Can catalyze epoxidation of fatty acid and sulfoxidation reactions that can proceede competitively, although in favor of the sulfoxidation. Can only use unsaturated fatty acids with double bonds in the cis configuration as substrates. The preferred substrate is oleic acid and is inactive toward ricinoleic acid. Free fatty acid and fatty acid methyl esters are effective substrate forms, but not phospholipids and acyl-CoA. Hydroperoxy-trienoic (HPOT) acids are preferred over Hydroperoxy-dienoic (HPODT) acids as oxygen donors. RH + ROOH = ROH + ROH. Binds 1 heme b (iron(II)-protoporphyrin IX) group. Inhibited by beta-mercaptoethanol and organophosphorothioates such as parathion or terbufos. Optimum pH is 7.0. Optimum temperature is 45 degrees Celsius. Homodimer. Expressed only in developing seeds. Not detected in roots, leaves, glumes and germinating seeds. Transmembrane regions are predicted by sequence analysis tools, but these regions probably constitute hydrophobic domains associated to phospholipids. The proline-knot motif (124-133) may be involved in targeting to lipid bodies. Belongs to the caleosin family.