The bacterium Mycoplasma pneumoniae, which causes atypical pneumonia, is helping scientists uncover how cells make the most of limited resources. By measuring all the proteins this bacterium produces, scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, and collaborators, have found that the secret is fine-tuning.
Like a mechanic can fine-tune a car after it has left the factory, cells have ways to tweak proteins, changing their chemical properties after production -- so-called post-translational modifications. Anne-Claude Gavin, Peer Bork and colleagues at EMBL measured how many of M. pneumoniae's proteins had certain modifications. They found that two forms of tweaking which were known to be common in our own cells are equally prevalent in this simple bacterium. Called phosphorylation and lysine acetylation, these two types of post-translational modification also talk to and interfere with each other: the scientists found that disrupting one can cause changes in the other. Since M. pneumoniae is one of the living organisms with the fewest different proteins, this interplay between phosphorylation and lysine acetylation may be a way of getting additional functions out of a limited number of proteins: by tweaking each protein in several ways, enabling it to perform a variety of tasks. And, as more complex cells like our own share the same protein-tweaking tactics, it is probably an ancient strategy that evolved before our branch of the evolutionary tree and M.pneumoniae's branched their separate ways.
Like a mechanic can fine-tune a car after it has left the factory, cells have ways to tweak proteins, changing their chemical properties after production -- so-called post-translational modifications. Anne-Claude Gavin, Peer Bork and colleagues at EMBL measured how many of M. pneumoniae's proteins had certain modifications. They found that two forms of tweaking which were known to be common in our own cells are equally prevalent in this simple bacterium. Called phosphorylation and lysine acetylation, these two types of post-translational modification also talk to and interfere with each other: the scientists found that disrupting one can cause changes in the other. Since M. pneumoniae is one of the living organisms with the fewest different proteins, this interplay between phosphorylation and lysine acetylation may be a way of getting additional functions out of a limited number of proteins: by tweaking each protein in several ways, enabling it to perform a variety of tasks. And, as more complex cells like our own share the same protein-tweaking tactics, it is probably an ancient strategy that evolved before our branch of the evolutionary tree and M.pneumoniae's branched their separate ways.
