Mammalian DNA Polymerase α Holoenzyme
DNA replication as a macromolecular process requires the concerted action of many enzymes and proteins either alone or in a complex (1). These include e.g. DNA polymerases, DNA polymerase accessory proteins, primase, topoisomerases, helicases, DNA-binding proteins, ribonuclease H, DNA ligase and others (1). Using the DNA of small bacteriophages of Escherichia coli and of plasmids containing the oriC as model replicons to understand the host DNA replication events, it was discovered that multienzyme systems are involved (1). The DNA elongation step alone needs DNA polymerase III, the major replicase in bacteria. DNA polymerase III functions in the form of a multipolypeptide complex called DNA polymerase III holoenzyme (2). The term holoenzyme has been introduced in Escherichia coli for a complex of proteins including a core DNA polymerase III and several auxiliary proteins, which are essential for replication of primed natural single stranded genoms (2). Many details of the structure and functions of this multipolypeptide complex have emerged during the last few years (3, 4).
KeywordsReplication Fork Core Enzyme Multienzyme System Holoenzyme Activity Primase Activity
Unable to display preview. Download preview PDF.
- 1.Kornberg, A. (1980, 1982 supplement) DNA replication, Freeman and Co. San Francisco.Google Scholar
- 3.Kornberg, A. (1984) this volume.Google Scholar
- 4.McHenry, C.S. and Johanson, K.O. (1984) this volume.Google Scholar
- 7.Hübscher, U. and Ottiger, H.-P. (1983) in: Mechanisms of DNA replication and recombination, Cozzarelli, N.R. ed., UCLA Symposia on Molecular and Cellular Biology, Alan R. Liss, Inc., New York Series, vol. X, 517.Google Scholar
- * An asymmetric dimeric replicative DNA polymerase III holoenzyme complex from Escherichia coli has concurrently been proposed by McHenry and Johanson (4).Google Scholar
- 11.Spanos, A. and Hübscher, U. (1983) in: Methods in Enzymology, Hirs, C.H.W. and Timasheff, S.N. eds., Academic Press, New York, 91, 263.Google Scholar
- 12.Ottiger, H.-P. and Hübscher, U. (1984) submitted for publication.Google Scholar