What are some of the characteristics of peroxisome: synthesis and breakdown of fatty acids, no genome, single bound membrane, division by fission. Animals cells: cholesterol synthesis, oxidation of fatty acids. Breakdown/oxidation of fatty acids to acetyl coa produces metabolic energy (plants and animals) Biproduct hydrogen peroxide, which is toxic to the cell. Peroxisomal proteins are synthesized in the cytosol and transported to a peroxisome. Luciferase is also found in the peroxisome; expressed in mammalian cells and it went to the peroxisome, pathway is conserved. Isolated a peroxisome targeting sequence (pts) in the amino acid sequence of luciferase. Pts1 = ser-lys-leu or skl at extreme c-terminus; peroxisomal-targeting sequence. Pts2- used by some peroxisomal proteins at n-terminus. If ser-lys-leu tripeptide is converted to ser-asn-leu, luciferase no longer goes to peroxisome: yes, pts1 is necessary b/c mutations in the signal sequence disrupts transport. Pts1+ gfp all gfp is transported into the peroxisomes. The wt motif can target a cytosolic protein to the peroxisome.