Purification and characterization of SP21, a development-specific protein of the myxobacterium Stigmatella aurantiaca.

Stigmatella aurantiaca is a gram-negative bacterium with a complex life cycle, including cellular aggregation resulting in the formation of a characteristic three-dimensional structure, the so-called fruiting body. During fruiting and upon chemical induction of sporulation, a major development-specific protein, SP21, is synthesized. SP21 was purified to homogeneity from the membranous fraction of chemically induced spores. Expression of SP21 was studied with an antiserum raised against the purified protein.