mtDNAencoded

mtDNAencoded is a term used in molecular biology and genetics to refer to genes that are encoded within the mitochondrial DNA (mtDNA). Mitochondria are organelles found in eukaryotic cells, often referred to as the "powerhouses" of the cell, responsible for generating most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy.

The mitochondrial genome is typically a circular molecule, separate from the nuclear genome. In humans, mtDNA is relatively small, containing 37 genes. These genes encode for essential components of the oxidative phosphorylation system, which is the primary process for ATP production. Specifically, mtDNA encodes 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), and 13 protein subunits that are part of the electron transport chain and ATP synthase complex.

The proteins encoded by mtDNA are crucial for cellular respiration. These include subunits of NADH dehydrogenase (complex I), cytochrome c oxidase (complex IV), and ATP synthase (complex V), as well as components of cytochrome b (complex III). While the majority of mitochondrial proteins are encoded by nuclear DNA and then imported into the mitochondria, the genes located within mtDNA are directly involved in the core machinery of energy production.

The inheritance of mtDNA is typically maternal, meaning it is passed down from the mother to her offspring through the egg cell. This maternal inheritance pattern is a key characteristic that distinguishes mtDNA from nuclear DNA. Mutations in mtDNA-encoded genes can lead to a variety of mitochondrial diseases, which often affect energy-intensive tissues such as the brain, muscles, and heart. The study of mtDNA-encoded genes is vital for understanding cellular metabolism, evolutionary biology, and the genetic basis of certain diseases.