During the last decade physical and chemical methods have improved
rapidly - a fact which allowed the mode of action of antibiotics to be
studied - and many biochemically-oriented scientists have devoted their
research to the following questions: 1. What is the metabolic pathway
that is inhibited selectively, and what are the target molecules within
a sensitive cell? 2. What are the relationships between the chemical
structure of an antibiotic and the physicochemical properties of the
sensitive mole- cule(s)? 3. Why and how far is the action selective? 4.
Is it possible to correlate the interaction with the target mole-
cule(s) with the particular biological activities observed? This
monograph deals with those antibiotics which interfere with the
biosynthesis of nucleic acids. The idea was to provide an insight into
how to investigate the preceding questions experimentally and to solve
as yet unresolved problems rather than to give a review of the current
state of knowledge. Although the biochemistry of nucleic acid synthesis
is known in general, the precise molecular mechanisms by which
deoxyribonucleic acid is replicated or transcribed has still to be
clarified. For this reason it is not yet possible to describe the
molecular mechanisms by which the inhibitors of nucleic acid and protein
synthesis exhibit their effects. The fact that the inhibitors of nucleic
acid and protein synthesis themselves served as useful tools to obtain
an insight into the mechanisms of replication, transcription and
translation was one of the most exciting discoveries in this field.