9309759 Webster When the hemoglobin gene (vgb) from the bacterium, Vitreoscilla, is present in recombinant E. coli carrying the gene for alpha- amylase from Bacillus stearothermophilus, the production of this enzyme is stimulated. The main objective of this project is to obtain basic information about the mechanism of this stimulation. The role of the product of vgb expression, Vitreoscilla hemoglobin (VtHb), will be examined using site-directed mutagenesis to produce inactive and altered proteins. These inactive and altered proteins will then be tested for a change in the stimulatory effect. VtHb increases under hypoxic conditions and presumably functions by facilitating respiration under these conditions. Other planned experiments include extending the basic findings to other products besides alpha-amylase, and to other bacterial systems.