DAGLEY AND SYKES 



69 



creased areas it appears that the components forming these boundaries may 

 contain the material that appears as 40 S at lower phosphate concentrations. In 

 0.066 M phosphate, the leading boundary sedimented at 40 S followed by 26 S 

 and 19 S at 10 mg protein/ml, but there was dissociation of the 40 S component 

 at 7.5 mg protein/ml. In 0.04 M phosphate, 40 S was stable at both concentra- 

 tions of extract. It is of interest that concentrations of phosphate above 0.06 M, 

 but not below, effect a loss of the 40 S components whether they are inside the 

 cells or in extracts isolated from them. This supports the evidence of Roberts 

 et al. [20] that the phosphate concentration inside E. coli does not differ greatly 

 from that outside. The final results of disintegration of the 40 S component, 

 however, are not the same in whole cells as in extracts, for 29 and 20 S com- 

 ponents appear to be the main disintegration products in extracts, whereas in 

 whole cells these peaks are not strongly augmented. It is possible that the ini- 

 tial split of 40 S is to give 29 and 20 S components and that in whole cells the 

 process goes further to produce lower-molecular-weight diffusible material. 



We are grateful to the Medical Research Council for their financial support 

 of this work. 



REFERENCES 



1. H. K. Schachman, A. B. Pardee, and 

 R. Y. Stanier, Arch. Biochem. Biophys., 

 38, 245 (1952). 



2. A. Siegel, S. J. Singer, and S. G. Wild- 

 man, Arch. Biochem. Biophys., 41, 278 

 (1952). 



3. D. Billen and E. Volkin, /. BacterioL, 

 67, 191 (1954). 



4. M. Stephenson, Bacterial Metabolism, 

 3d ed., p. 311, Longmans, Green and Com- 

 pany, London, 1949. 



5. D. E. Hughes, Brit. J. Exptl. Pathol., 

 32, 97 (1951). 



6. S. Dagley and J. Sykes, Arch. Bio- 

 chem. Biophys., 62, 338 (1956). 



7. E. F. Gale, Advances in Enzymol., 6, 

 1 (1946). 



8. J. Lederberg, /. BacterioL, 60, 381 

 (1950). 



9. E. Englesberg, J. B. Levy, and A. 

 Gibor, /. BacterioL, 68, 178 (1954). 



10. E. Englesberg and J. B. Levy, /. Bac- 

 terioL, 69,418 (1955). 



11. R. Wolfe and J. Nielands, /. Biol. 

 Chcm., 221, 61 (1956). 



12. M. Dixon and J. Moyle, Biochem. ]., 

 63, 548 (1956). 



13. V. Massev, Biochem. J., 51, 490 

 (1952). 



14. R. Cecil and A. G. Ogston, Biochem. 

 J., 51, 494 (1952). 



15. M. Cohn, BacterioL Revs., 21, 140 

 (1957). 



16. A. G. Callely, S. Dagley, and B. 

 Hodgson, Biochem. J., 66, 47P (1957). 



17. F. Lynen and S. Ochoa, Biochim. et 

 Biophys. Acta, 12, 299 (1953). 



18. H. E. Wade and D. M. Morgan, 

 Biochem. /., 65, 321 (1957). 



19. M. Webb, /. Gen. Microbiol., 3, 410 

 (1949). 



20. R. B. Roberts, P. H. Abelson, D. B. 

 Covvie, E. T. Bolton, and R. J. Britten, 

 Studies of Biosynthesis in Escherichia coli, 

 Carnegie Inst. Wash. Publ. 607, Washing- 

 ton, D. C, 1955. 



