Proteins that interact with GTP in Streptomyces griseus and its possible implication in morphogenesis

By cross-linking with [alpha-32P]GTP or [gamma-32P]GTP with or without UV treatment, several proteins of Streptomyces griseus were shown to interact with GTP in specific ways. After gel electrophoresis, 19 bands of radioactivity were found; 12 bands were assigned as GTP-binding proteins and 6 bands as phosphorylated proteins. One band was assumed to be a guanylylated protein. The profile of radioactive bands was similar between cells prepared from liquid or solid culture, but markedly different between growth phases. A mutant (strain M-1) defective in aerial mycelium formation, which was originally found as a decoyinine-resistant isolate, was found to have a different profile of phosphorylated proteins.