Our continuing studies of the bacteriophage f1 will be concentrated on two areas of phage biology , its DNA synthesis and its assembly. Both of these areas bring to the fore the two fundamental biological problems for which the study of viruses can be especially useful. These involve questions about the assembly and interaction of multi-protein and nucleic acid structures and inquires into the basic aspects of the higher order elements of cell metabolism. We have found that the E. coli integration host factor (IHF) plays an important role in the synthesis of the phage plus (viral) strand. It appears to act just after the start of DNA synthesis, perhaps altering the structure of the DNA so that synthesis can proceed. Available are appropriate mutant DNA's, purified IHF and the usual components of DNA synthesis to dissect this reaction in detail. Phage assembly depends on the presence and interaction of a cis-acting, phage DNA signal and some phage and some host proteins. These are all hand and their interrelationships under study. Currently, we are intrigued by a protein induced in the host by one of the phage's morphogenetic proteins, pIV. This phage shock protein is being cloned, sequenced and its role in phage and host metabolism being ascertained by careful manipulations of this E. coli gene. This protein falls into the class of host stress-induced proteins. Although still obscure, this protein may provide the most valuable clue we have to date on the role of the phage's gene IV.
