Expression and properties of bacteriophage T4 gene product 11

A plasmid vector for expression of bacteriophage T4 gene product 11 (gp 11) in E. coli cells has been constructed. Gp 11 is a baseplate protein that c onnects short tail fibers providing irreversible adsorption of the virus on a cell. A method based on chromatography on hydroxyapatite has been develo ped for purification of recombinant gp 11. The protein is active in an in v itro complementation assay and transforms defective phage particles lacking gp 11 into infective ones. Gel filtration data suggest that the biological ly active protein is a trimer. According to CD spectroscopy and sequence an alysis data, the polypeptide chain of gp 11 contains not less than 20% alph a -helical segments, about 30% beta -structure, and belongs to the class of alpha/beta structural proteins.