ROLE OF HOST IN VIRUS ASSEMBLY - CLONING OF ESCHERICHIA-COLI GROE GENE AND IDENTIFICATION OF ITS PROTEIN PRODUCT

Correct assembly of the heads of bacteriophages λ and T4 requires the function of the groE gene of the Escherichia coli host. We have isolated a transducing derivative of λ, called λgt-Ec.groE, that carries a functional copy of the groE gene. Unlike wild-type λ, this phage is able to form plaques on hosts with a mutant groE gene. We have isolated an amber mutation in the groE gene carried by the phage, and this has made it possible to identify the groE product as a protein of molecular weight 65,000. In the phage, the groE gene is under the control of an early phage promoter.