Fig. 5.

Glycine cleavage activitites of the A. aeolicus GcvH homologs. The medium was a modified Spizizen salts that lacked ammonium sulfate and was supplemented with glucose, 0.01% each of l-phenylalanine and l-tryptophan and 0.015% acid hydrolyzed casein. Either glycine or l-glutamic acid (a preferred nitrogen source for this bacterium) was added at 0.1%. The plates were incubated at 37 °C for 72 h. No discrete colonies were formed by the strains that expressed GcvH1 and GcvH2 (the imperfections are scratches from the streaking), whereas barely visible colonies were formed within the scratches by the strain that expressed GcvH5. Note that this figure is a collage of scans.