Formation of Ribonucleic Acid during the Recovery of the Deoxyribonucleic Acid Synthetic System of Bacteria damaged by Ultra-violet Light

Abstract

A REQUIREMENT for RNA and protein, synthesis in recovery of the DNA synthetic system of Escherichia coli damaged by ultra-violet light (UV) has been demonstrated^1–4. At that dose of ultra-violet light producing the maximum possible delay in DNA synthesis without non-restorable inactivation, an approximate doubling of RNA occurs before initiation of DNA synthesis⁴. If chloram-phenicol, an antibiotic which blocks protein synthesis, is added before the doubling of RNA, DNA synthesis proceeds, after the completion of the restoration period, at a reduced, non-accelerating rate directly related to the increase in RNA between the time of exposure to ultraviolet light and the time of adding chloramphenicol⁴.