An organism that has been around from 2 billion years ago has given biologists from Centre for Cellular and Molecular Biology, Hyderabad (CCMB), a clue as to how mitochondria became an inseparable part of animal and plant cells. The researchers, led by Rajan Sankaranarayanan, identify two key transformations, one in the molecule known as DTD for short and another in the transfer-RNA (tRNA).
“Our lab works on a molecule called D-aminoacyl-tRNA deacylase (DTD). We observed some unexpected biochemistry of eukaryotic DTD that could be explained based on endosymbiotic origin of complex eukaryotic cell organelles.” Endosymbiosis is an intense form of symbiosis when one of the organisms is captured and internalized by the other.
Today, mitochondria are well known to be integral parts of the eukaryotic cell. They are dubbed the power houses of the cell, because they help in generating energy in the form of ATP within the cell, powering it. But they were not always part of the animal and plant cells. Once, about two billion years ago, a prokaryotic organism (without a nucleus) called archaea captured a bacterial cell. The bacterial cell learnt to live within the archaea as an endosymbiont. How this happened has been an important question among biologists. “In the late 19th century, microscopists observed that organelles like chloroplast [and later mitochondria] undergo division inside eukaryotic cells that resembles bacterial division, which led them to suspect that these organelles might have arisen from bacterial endosymbionts,” say Jotin Gogoi and Akshay Bhatnagar from CCMB and the first authors of the paper published in Science Advances.
