Optimization for self-production may explain key features of ribosomes, the protein production factories of the cell, reported researchers from Harvard Medical School in Nature on July 20.
In a new study, a team led by Johan Paulsson, professor of systems biology at Harvard Medical School, mathematically demonstrated that ribosomes are precisely structured to produce additional ribosomes as quickly as possible, in order to support efficient cell growth and division.
Ribosomes are composed of a puzzlingly large number of different structural proteins — anywhere from 55 to 80, depending on organism type. These proteins are not just more numerous than expected, they are unusually short and uniform in length. Ribosomes are also composed of two to three strands of RNA, which account for up to 70 percent of the total mass of the ribosome.
“An analogy for our findings would be to think of ribosomes not as a group of carpenters who merely build a lot of houses, but as carpenters who also build other carpenters,” Paulsson said. “There is then an incentive to divide the job into many small pieces that can be done in parallel to more quickly assemble another complete carpenter to help in the process.” Paper. (paywall) – Shlomi Reuveni, Måns Ehrenberg, Johan Paulsson. Ribosomes are optimized for autocatalytic production. Nature, 2017; 547 (7663): 293 DOI: 10.1038/nature22998 More.
Note: Posting light till this evening due to O’Leary for News’s alternate other day job.
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