Bacteriophage tail components. V. Complementation of T4D gene 28 - -infected bacterial extracts with pteroyl hexaglutamate.

Synthetic pteroyl hexaglutamate (9 x 10(-6) M) stimulated the formation of new T4D particles in vitro in extracts of Escherichia coli B infected with T4D gene 28(-). The stimulation was specific for this form of folic acid since neither pteroyl pentaglutamate nor pteroyl heptaglutamate stimulated phage formation. T4D formation in vitro in E. coli B extracts prepared after infection with 11 other phage mutants known to be involved in phage tail plate formation (5(-), 6(-), 7(-), 8(-), 10(-), 25(-), 26(-), 27(-), 29(-), 51(-), 53(-)) was not stimulated by the addition of pteroyl hexaglutamate. It can be concluded that the T4D gene 28 product is involved in the formation of the phage tail plate pteroyl hexaglutamate.