"You are more closely related to a fruit fly than these two organisms are to each other," he says.
However, from analysis of genes from the two bacteria, McBride suspects that they use the same basic machinery to move.
And there may be another connection. F. johnsoniae doesn't eat cellulose, but it is able to digest a similar carbohydrate polymer, chitin. Like cellulose, chitin, which is found in the hard shells of lobsters and insects, is also difficult to break down.
McBride hypothesizes that digestion of cellulose and chitin may also be linked to cell movement, or motility.
"Loss of motility results in loss of ability to digest chitin," he says. "This suggests that motility and digestion of some carbohydrate polymers may be connected in both gliding microbes."
McBride and his students have used F. johnsoniae to study the motility of gliding bacteria for more than a decade. They cloned "mutants" of F. johnsoniae that are unable to move, and then attempted to "repair" them by inserting certain pieces of DNA.
In this way, they have uncovered nearly all the genetic components that propel the cells. It has been a long process. A decade ago, his lab had found one protein involved. He now knows of 24, and he doesn't expect to find many more.
Until recently, McBride was not able to image the bacteria closely enough to see the structures involved in movement. Instead, he bonded latex spheres to the surface of F. johnsoniae cells and observed that they moved in all directions around the cell's perimeter.
"The cell wall appears to have a series of moving conveyer belts," he says.
He also has learned that some of the motility proteins ("parts") act at the surface of the cell, and he thinks some are involved in forming nearly invisible filaments around the perimeter of t
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Source:University of Wisconsin - Milwaukee