This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Zerial, A Articles by Firshein, W Search for Related Content PubMed PubMed Citation Articles by Zerial, A Articles by Firshein, W

Glycolipids stimulate DNA polymerase activity in a DNA-membrane fraction and in a partially purified polymerase system extracted from pneumococci.

ABSTRACT

We have assayed the ability of various lipids to affect DNA polymerases activity in a DNA-membrane complex extracted from Streptococcus pneumoniae by the Sarkosyl-M-band technique. In addition, to determine which DNA polymerases were affected by the lipids, we partially purified three DNA polymerase activities from cell lysates, the first such demonstration outside of Escherichia coli and Bacillus subtilis. Glycolipids are unique among polar lipids in stimulating the rate and extent of DNA polymerase activity in M-bands and in Sarkosyl lysates from which the M-band is derived. It appears that they exert this stimulatory effect, in part, by removing (neutralizing) detergent molecules which act as inhibitors, as well as by substituting for the detergent, thereby creating a favorable environment for the polymerases involved in DNA synthesis. That the stimulatory effect is not simply a detoxification of the detergent was shown by two observations. One, phospholipids, although interacting with Sarkosyl and therefore "potentially" capable of detoxifying the system, did not stimulate DNA polymerase activity in vitro. Two, glycolipids were capable of stimulating the activity of at least two DNA polymerases partially purified from cell lysates in the absence of any Sarkosyl. The stimulatory effect was greater for a polymerase that had four characteristics similar to those observed with polymerase III in other organisms.