Purified preparations of complete T4 bacteriophage, tail fiberless particles, whole tail fibers and four tail fiber precursors were dissociated by heating briefly at 100 °C in 1% sodium dodecyl sulfate containing 1% mercaptoethanol. Analysis of the dissociated structures by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and mercaptoethanol revealed two high molecular weight (150,000 and 123,000 daltons) polypeptides as major tail fiber components. These two components could be easily identified by autoradiography of sodium dodecyl sulfate gels of radioactively labeled infected cell extracts. The larger of the two was missing from extracts of cells infected with gene 34 amber mutants, and the smaller from extracts of cells infected with gene 37 amber mutants. It is concluded that the two components represent the products of genes 34 and 37 (P34 and P37), respectively. Molecular weight calculations indicate that two copies of each polypeptide are present in each complete tail fiber. Amber mutations in genes 38 and 57 were found to affect the apparent solubility of P34 and P37 and their resistance to dissociation in cold sodium dodecyl sulfate, but not their synthesis. Based on these results, the previously reported pathway of tail fiber assembly (King & Wood, 1969) has been reformulated in more detail.
|Journal||Journal of Molecular Biology|
|State||Published - Dec 28 1971|
Bibliographical noteFunding Information:
We thank William B. Wood and Frederick A. Eiserling for their support throughout the course of this work and for their critical reading of the manuscript. We have had benefit from discussions with Norman R. Davidson and Jerome Vinograd and our colleagues in the laboratory. We thank Margaret Novitski and Sandra L. Barnes for capable teeh-nical assistance and thank Jonathan King and Uli K. Laemmli for communicating their results before publication. This research was supported by U.S. Public Health Service grants GM 06965 and AI 09238 to William B. Wood and National Science Foundation grant GB 13117 and a grant from the Cancer Research Fund of the University of California to Frederick A. Eiserling. One of us (R. C. D.) was supported by U.S. Public Health Service grant GM 1331-03 and the other (S. W.) by the Mary K. Beschorman Fund for Biology.
ASJC Scopus subject areas
- Structural Biology
- Molecular Biology