Regulation of D-arabinose utilization in Escherichia coli K-12.

Studies involving lambda phage transduction of the D-arabinose utilization gene (dar+) in Escherichia coli K-12 indicated the product of this gene to be a transdominant activator. An apparent anomaly regarding this hypothesis exists in that a diploid recessive lysogen (lambda dar-/dar-) can spontaneously become capable of growth on D-arabinose.