Molecular Machine Parts Stockpiled in Readiness for Assembly
A team from the European Molecular Biology Laboratory has done a “4D” time-and-materials study of molecular machines, analyzing the process of assembly, reports EurekAlert. They found that the cell stockpiles some parts and holds them in storage, but adds the crucial elements just in time.
The researchers discovered that in yeast, key components needed to create a machine are produced ahead of time, and kept in stock. When a new machine is needed, a few crucial last pieces are synthesized and then the apparatus is assembled. Holding off on the last components enables the cell to prevent building machines at the wrong times. That’s a different scenario from what happens in bacteria, which usually start production of all the parts, from scratch, whenever they want to get something done.
“We saw a clear pattern as to how the complexes are assembled,” says Søren Brunak from DTU. It’s unusual to find such concrete patterns in biology, compared to physics for example, due to the evolutionary forces that change living systems. But using this new model, the underlying principle became very clear.” (Emphasis added in all quotes.)
The authors next want to find out how long components stay around after use. Their results were published in Science1 Feb. 4; see also the brief on EurekAlert.
1Lichtenberg et al., “Dynamic Complex Formation During the Yeast Cell Cycle,” Science, Vol 307, Issue 5710, 724-727, 4 February 2005, [DOI: 10.1126/science.1105103].
What would you want to bet that they will find out bacteria have assembly processes just as complex as those in eukaryotes? Planning ahead for future need, machinery, assembly; that doesn’t sound like the language of chance.