1. 1. Gellert, M. A. Rev. Biochem. 50, 879–910 (1981). 2. Luchnik, A. N., Bakayev, V. V., Zbarsky, I. B. & Georgiev, G. P. EMBO J. 1, 1353–1358 (1982). 3. Harland, R. M., Weintraub, H. & McKnight, S. L. Nature 302, 38–43 (1983). 4. Weintraub, H., Cheng, P. F. & Conrad, K. Cell 46, 115–122 (1986). 5. Wang, J. C. A. Rev. Biochem. 54, 665–699 (1986). 6. Vosberg, P.–H. Curr. Top. Microbiol. Immun. 114, 19–102 (1985). 7. Bonven, B. J., Gocke, E. & Westergaard, O. Cell 41, 541–551 (1985). 8. Christiansen, K., Bonven, B. J. & Westergaard, O. /. molec. Biol. 193, 517–525 (1987). 9. Gilmour, D. S. & Elgin, S. C. R. Molec. cell. Biol. 7, 141–148 (1987). 10. Kirkegaard, K. & Wang, J. C. Cell 23, 721–729 (1981). 11. Been, M. D., Burgess, R. R. & Champoux, J. J. Nucleic Acids Res. 12, 3097–3114 (1984). 12. Maxam, A. M. & Gilbert, W. Meth. Enzym. 65, 499–560 (1980). 13. Shure, M., Pulleyblank, D. E. & Vinograd, J. Nucleic Acids Res. 4, 1183–1205 (1977).