The factor which aggregates nematode, yeast and liver phosphoglycerate kinase in tRNA

1. A factor isolated from the free-living nematode, Turbatrix aceti and from yeast, causes aggregation of phosphoglycerate kinase from nematodes, yeast and rat liver. The rat muscle enzyme is not affected. 2. The aggregation factor is either identical to or very similar to tRNA, Pure tRNA from yeast or Escherichia coli, when mixed with nematode, yeast or rat liver phosphoglycerate kinase causes the enzyme to aggregate to higher mol. wt forms. Both the natural factor and tRNA bring about similar changes in the behavior of nematode phosphoglycerate kinase. 3. The tRNA does not remain bound to the enzyme though it appears to cause a sequential aggregation from monomer to tetramer. 4. No conclusion could be reached as to whether the factor plays a physiological role or if it is simply tRNA fortuitously present during purification of the enzyme.