glnA mutations define the structural gene for glutamine synthetase in Aspergillus

Five allelic glutamine auxotrophs of Aspergillus have been assayed for glutamine synthetase activity. The amounts of glutamine synthetase activity present in these strains were proportional to their ability to grow in the absence of L-glutamine, whereas the amount of γ-glutamyl transferase did not correlate with the amount of synthetase or with the growth properties. Two out of this sample of mutants have been shown to have a glutamine synthetase with a K m for L-glutamate which differs from the wild type.