In reading the following excerpt from a Cal Berkeley newsletter, ask yourself what contribution, if any, conventional evolutionary theory is making to the study of these biochemical systems. As an acceptable answer, try NIL.
In recent years Oster and his colleagues created a groundbreaking model of ATP synthase, an enzyme that synthesizes ATP, the universal fuel molecule that powers all cells. ATP synthase is essentially a factory built around two rotary motors. One of the motors forces the other to rotate as a generator that cranks out ATP. Oster’s contribution was in showing how the two motors generate their torque from very different fuel sources.
The first motor is essentially electric. It’s powered, Oster explains, by a transmembrane electro-chemical potential that drives the flow of ions across the cellular membrane. The other motor is powered by ATP, the same substance that the enzyme produces.
Of course, ATP synthase is only one of nature’s many protein motor systems. Working with UC Berkeley professor Carlos Bustamante, researchers have also studied the motor that packs a virus’s DNA so tightly that it can be injected into a hijacked cell at ten times the pressure of a cork shooting out of a champagne bottle. And they’ve modeled the donut-shaped molecular motors that move along DNA strands during replication.
The biomolecular portal motor of bacteriophage PHI-29 (yellow) compresses the coiled DNA into the viral capsid at 6,000 times its normal pressure. “The cylinders all operate in sequence like an old-fashioned airplane motor,” Oster says.
As the researchers better understand how, say, bacteria propel themselves, they’re also investigating where the organisms’ motility takes them. When hundreds of thousands gather together, Oster says, they can signal each other to “self-organize into elaborate structures that are symmetrical and beautiful,” while also serving a biological purpose. But what are those rules of higher-level organization? And what might they tell us about higher-level organisms that coordinate their own collective activities?
It’s these kinds of nested puzzles that keep Oster fascinated, he says.