The N terminal presequence domain found in 5-aminolevulinate synthase exists as an amphipathic helix, with a positively charged surface provided by lysine residues and no stable helix at the N-terminus. The domain is essential for the import process ...
The N terminal presequence domain found in 5-aminolevulinate synthase exists as an amphipathic helix, with a positively charged surface provided by lysine residues and no stable helix at the N-terminus. The domain is essential for the import process by which ALAS is transported into the mitochondria: translocase of the outer membrane (Tom) and translocase of the inner membrane protein complexes appear responsible for recognition and import through the mitochondrial membrane. The protein Tom20 is anchored to the mitochondrial outer membrane, and its interaction with presequences is thought to be the recognition step which allows subsequent import [1].