Genetic Analysis of Transfer by the Escherichia coli Sex Factor F, Using P1 Transductional Complementation

Abstract

P1 transduction has been used to perform a complementation analysis of a series of transfer-deficient mutants of F lac . The results define ten cistrons and are consistent with the results of a conjugational analysis presented in an accompanying report. Both sets of results are summarized here. Between them, they define eleven cistrons, traA through traK , necessary for conjugational deoxyribonucleic acid (DNA) transfer. Mutants in traI and traD and some in traG still make F-pili, although traD mutants are resistant to f2 phage; their products may be involved in conjugational DNA metabolism. Other mutants in traG and all mutants in the remaining eight cistrons do not make F-pili. One of these, traJ , may be a control cistron, and the others may specify a biosynthetic pathway responsible for synthesis and modification of the F-pilin subunit protein and its assembly into the F-pilus.