Scientific Breakthrough

Two Montreal researchers have proposed a new theory for a question that has long vexed evolutionary biologists: How did a mechanism thought to help build life self-assemble?

Sergey Steinberg, a biochemistry professor at the University of Montreal, found the answer in the ribosome, a relatively large mechanism within the cell that takes RNA instruction and builds proteins.

Steinberg and Bokov's theory fills in a critical step in how life got started four billion years ago, said Stephen Michnick, the Canada Research Chair in Integrative Genomics at the University of Montreal.

A key breakthrough came when Steinberg found that chemicals could spontaneously come together and form something as complex as a ribosome. Previous theories had suggested only simple proteins could form spontaneously.

Steinberg found the ribosome was put together using relatively simple structural rules, a bit like a three-dimensional puzzle.

For critics who ask why spontaneous formation didn't lead to something other than the ribosome, Steinberg used mathematical models to show there was no other possibility. The ribosome simply wouldn't hold together if it were constructed any other way.

His discovery, made with student Konstantin Bokov, has been published in the scientific journal Nature.