ABSTRACT
The evidence for microcompartmentation of DNA precursors was developed in prokaryotic systems. At least three factors led to the emphasis on prokaryotes; the experimental focus upon prokaryotes for study of DNA replication; kinetic aspects of DNA replication which all but demanded the existence of compartmentalized precursor pools; and the existence of a nuclear barrier in eukaryotic cells, which seemed to make microcompartmentation unnecessary. The idea of multienzyme complexes to channel metabolism, seems so logical and straightforward that one might propose accepting it as a guiding principle, even in the absence of experimental data. In fact, the data accumulated on the T4 system, primarily by the Greenberg laboratory and the Mathews laboratory, strongly support the channeled synthesis of deoxyribonucleoside 5’-triphosphates. In the mid-1970s, several lines of evidence converged about the concept that deoxyribonucleotides are synthesized by multienzyme complexes which are juxtaposed with, or maybe part of, the replication machinery.
