Abstract
c-type cytochromes are electron transfer proteins that are essential for the life of virtually all organisms. They characteristically carry covalently-bound heme via thioether bonds to two cysteines in the protein. In Gram-negative bacteria, biogenesis of c-type cytochrome is conducted by a multiprotein complex system known as the cytochrome c maturation (Ccm) system. This system is consisted of 8 gene products (CcmA-CcmH). CcmE, which is called as a heme chaperon, binds heme and delivers it to apocytochrome c. In this article, I discuss the structure of CcmE and how it works as a heme chaperone protein.
