Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 25, 1973 | public
Journal Article

Properties and Mode of Action of a Partially Purified Deoxyribonucleic Acid Polymerase from the Mitochondria of HeLa Cells


A DNA polymerase has been partially purified from the mitochondria of HeLa cells. Properties, including low levels of nuclease activity and a preference for native duplex DNA templates, were favorable for the study of in vitro DNA synthesis using circular duplex DNA templates. Initiation of DNA synthesis occurs predominantly at sites of single strand scissions with covalent addition of nucleotides to the priming template strand. Centrifugation and electron microscopy have established that the template DNA strand ahead of the growing point is displaced rather than degraded. Hairpin structures are not formed in the course of DNA synthesis on duplex DNA templates.

Additional Information

© 1973 American Society of Biological Chemists, Inc. Received August 25, 1972. This investigation was supported by United States Public Health Service Grants CA08014 from the National Cancer Institute and GM15327 from the National Institute of General Medical Sciences. This is contribution No. 4529 from the Division of Chemistry and Chemical Engineering. We thank J. Edens and P. Koen for expert technical assistance and advice. We also thank R. Summers for preparation of the manuscript.

Additional details

August 19, 2023
October 18, 2023