Joyce Emrich

Lysis of T4-infected bacteria in the absence of lysozyme.

Abstract A mutant of phage T4 has been found which permits lysis of infected bacteria in the absence of lysozyme. The new mutation may affect a phage-directed synthesis of bacterial cell wall components; hence the name spackle (s).

The role of phage lysozyme in the life cycle of phage T4.

The lysozyme that is synthesized under the direction of the e gene of phage T4 is known to cause the lysis of infected bacteria. In this paper we show that this lysozyme plays no detectable role in infection or in lysis from without. We also mention the detection of a heretofore undescribed lytic activity that is associated with mature phage particles.

Frameshift mutations resulting in the changes of the same amino acid residue (140) in T4 bacteriophage lysozyme and in vivo codons for Trp, Tyr, Met, Val and Ile.

Abstract The lysozymes of three new strains of double frameshift mutants of T4 bacteriophage, e J37 e JD3, e J200 e JD4 and e J25 e JD1, were isolated from their respective lysates, and their amino acid sequences were compared with that of the wild-type strain. It was found that Trp 138 -Tyr-Asn 140 in wild-type lysozyme changes to Met-Val-Tyr in e J37 e JD3, Tyr 139 -Asn 140 to Cys-Ile-Ile in e J200 e JD4 and Asn 140 to Ile-Ile in e J25 e JD1. From these results, a new hot spot for frameshift mutations has been found at Asn 140 and in vivo codons for Trp, Tyr, Met, Val and Ile are thought to be UGG, UAU, AUG and AUA, respectively. Nineteen in vivo codons out of 64 codons have been identified by these results together with our previous results.

Direction of translation of the lysozyme gene of bacteriophage T4 relative to the linkage map

Abstract The lysozyme gene of bacteriophage T4 has been shown to be translated in the same direction as the rII gene and in a direction opposite to that of the head gene. The time of translation of genes of bacteriophage T4 seems not to be determined by the direction of translation.