cytosolic proteins that are produced with the PTS1 C-terminal sequence, its path to the peroxisomal matrix is dependent upon binding to another cytosolic protein called pex5 (peroxin 5). Once bound, pex5 interacts with a peroxisomal membrane protein pex14 to form a complex. When the pex5 protein with bound cargo interacts with the pex14 membrane protein, the complex induces the release of the targeted protein into the matrix. Upon releasing the cargo protein into the matrix, pex5 dissociation from pex14 occurs via ubiquitinylation by a membrane complex comprising pex2, pex12, and pex10 followed by an ATP dependent removal involving the cytosolic protein complex pex1 and pex6. The cycle for pex5 mediated import into the peroxisomal matrix is restored after the ATP dependent removal of ubiquitin and is free to bind with another protein containing a PTS1 sequence. Proteins containing a PTS2 targeting sequence are mediated by a different cytosolic protein but are believed to follow a similar mechanism to that of those containing the PTS1 sequence. Diseases Protein transport is defective in the following genetic diseases: Mohr–Tranebjaerg syndrome Zellweger syndrome Adrenoleukodystrophy (ALD). Refsum disease Parkinson's disease Hypercholesterolemia, atherosclerosis, obesity, and diabetes In bacteria and archaea As discussed above (see protein translocation), most prokaryotic membrane-bound and secretory proteins are targeted to the plasma membrane by either a co-translation pathway that uses bacterial SRP or a post-translation pathway that requires SecA and SecB. At the plasma membrane, these two pathways deliver proteins to the SecYEG translocon for translocation. Bacteria may have a single plasma membrane (Gram-positive bacteria), or an inner membrane plus an outer membrane separated by the periplasm (Gram-negative bacteria). Besides the plasma membrane the majority of prokaryotes lack membrane-bound organelles as found in eukaryotes, but they may assemble proteins onto various types of inclusions such as gas vesicles and storage granules. Gram-negative bacteria In gram-negative bacteria proteins may be incorporated into the plasma membrane, the outer membrane, the periplasm or secreted into the environment. Systems for secreting proteins across the bacterial outer membrane may be quite complex and play key roles in pathogenesis. These systems may be described as type I secretion, type II secretion, etc. Gram-positive bacteria In most gram-positive bacteria, certain proteins are targeted for export across the plasma membrane and subsequent covalent attachment to the bacterial cell wall. A specialized enzyme, sortase, cleaves the target protein at a characteristic recognition site near the protein C-terminus, such as an