mtDNA makes a U-turn for the mitochondrial nucleoid

作者：Kukat Christian; Larsson Nils Goeran^*

来源：Trends in Cell Biology, 2013, 23(9): 457-463.

DOI：10.1016/j.tcb.2013.04.009

• mitochondrial nucleoid
• mtDNA
• TFAM

Mitochondria contain mtDNA derived from the ancestral endosymbiont genome. Important subunits of the oxidative phosphorylation system, which supplies cells with the energy currency ATP, are encoded by mtDNA. A naked mtDNA molecule is longer than a typical mitochondrion and is therefore compacted in vivo to form a nucleoprotein complex, denoted the mitochondrial nucleoid. Mitochondrial transcription factor A (TFAM) is the main factor packaging mtDNA into nucleoids and is also essential for mtDNA transcription initiation. The crystal structure of TFAM shows that it bends mtDNA in a sharp U-turn, which likely provides the structural basis for its dual functions. Super-resolution imaging studies have revealed that the nucleoid has an average diameter of similar to 100 nm and frequently contains a single copy of mtDNA. In this review the structure of the mitochondrial nucleoid and its possible regulatory roles in mtDNA expression will be discussed.

• 出版日期2013-9