Schematic representation of human mtDNA control region. Complete mtDNA control region is divided into the regulatory control region (RCR, located between nt 1 and 576) and the hypervariable control region (HCR, located between nt 16024 to 16569). OH , the origin of the heavy (H)-stand DNA replication; HSP, the promoter for the H-strand; LSP, the promoter for the light (L)-strand; TFAM, transcription factor A mitochondrial binding sites; CSBs, conserved sequence blocks I, II and III; TAS, termination associated sequence.