The nuclear localization signal is not removed following transport into the nucleus. Peroxisomal proteins contain an internal target sequence consisting of basic amino acids that is not removed following transport into peroxisomes. The most common peroxisomal target sequence is at the C-terminus and is not removed following transport. Transport of peroxisomes does not require a membrane potential. Mitochondrial DNA is double-stranded and circular like many bacterial DNA's.
Mitochondria utilize a slightly different genetic code than does the nucleus.
Proteins targeted to the thylakoid lumen contain a second target sequence after the first . Parallel arrays of actin filaments are called bundles and are held together by actin binding proteins like fascin . Arrays of actin filaments that cross each other at various angles are called networks and are held together by flexible actin binding proteins such as filamin . 16 Carbohydrate is added to protein in the ER lumen and modified in the Golgi . A plasma membrane glycoprotein will have its carbohydrate exposed on the extracellular surface .