Protein synthesis during fungal spore germination. I. Characteristics of an in vitro phenylalanine incorporating system prepared from germinated spores of Bofryodiplodia theobromae

The characteristics of an in vitro amino acid incorporating system prepared from germinated spores of Botryodiplodia theobromae are described. Phenylalanine incorporation was dependent on ribosomes, a 105,000g supernatant fraction, poly U, sRNA, an ATP generating system, and magnesium concentration. The activity of the system was enhanced by adding ammonium, GTP, and spermine. The incorporation of phenylalanine was inhibited by ribonuclease, puromycin, and actidione, but deoxyribonuclease, chloramphenicol, streptomycin, and neomycin had essentially no effect. Poly A and poly C did not stimulate phenylalanine incorporation. In addition, lysine, isoleucine, and proline incorporation was not stimulated by poly U. A similar system prepared from ungerminated spores was inactive in incorporating phenylalanine. Interchanging ribosomes and the 105,000g supernatant fraction from germinated and ungerminated spores indicated that the defect in the extract from the uingerminated spores was in the 105,000g supernatant fraction.