STUDIES OF MUTATIONS IN T4 CONTROL GENES 33 AND 55

[摘要] Available mutations in transcriptional control genes 33 and 55 of coliphage T4 have been examined. By complementation analysis and map position, 15 mutants (13 in T4D, 2 in T4B) have been shown to lie in gene 33 and 6 (5 in T4D, 1 in T4B) in gene 55 . According to patterns of suppression and recombination, these mutants define three distinct amber sites in gene 33 and also three distinct amber sites in gene 55 . All of these mutations are true amber mutations, in apparent contrast to some traditional T4 "amber" mutants which grow in su+ E. coli CR63 but not in su- E. coli B because of a strain difference other than the su+ determinant. Evidence is presented that, contrary to previous suggestions (Bolle et al . 1968; Pulitzer and Geiduschek 1970), the gene 33 product is absolutely essential for T4 development.

[学科分类] 医学（综合）