VIRION POSITIONS AND RELATIONSHIPS OF LACTOCOCCAL TEMPERATE BACTERIOPHAGE-TP901-1 PROTEINS

The major proteins of phage TP901-1 virion were characterized by sodiu m dodecyl sulfate-polyacrylamide gel electrophoresis and structural re lations were determined using specific antibodies, obtained by affinit y purification from a polyclonal serum. A 23-kDa protein was identifie d as the major tail protein, and a 31-kDa molecule as the major head p rotein, respectively. Labeling experiments with antibodies against two proteins, with molecular masses of 20 and 19 kDa, indicated that they were baseplate-related components. A 72-kDa protein was found to be p art of a neck passage structure, which includes a collar. Evidence for the presence of attached whiskers was also obtained. T7 RNA polymeras e-mediated expression of the two major proteins confirmed the gene loc ation of the previously sequenced region of the phage genome. The rela tion to other lactococcal phages was determined by DNA hybridization a nd antibody probing, showing that despite low DNA similarity, TP901-1 NPS epitopes were detected in both related and unrelated small isometr ic-headed phages. (C) 1995 Academic Press, Inc.