PARTIAL-PURIFICATION AND CHARACTERIZATION OF THE DNA-POLYMERASE FROM THE CYANELLES OF CYANOPHORA-PARADOXA

A DNA polymerase was partially purified and characterized from the pho tosynthetic organelles (cyanelles) of the protist, Cyanophora paradoxa . While cyanelles have several cyanobacterial features, such as a lyso zyme-sensitive cell wall, unstacked thylakoids and light harvesting ph ycobilisomes, their genome size and structure resemble those of chloro plasts, suggesting that cyanelles occupy a unique intermediate positio n between chloroplasts and their phylogenetic ancestors, the cyanobact eria, When comparing the biochemical characteristics of the cyanelle D NA polymerase to those of its counterparts from higher plant chloropla sts and from a cyanobacterium, it is clear that the cyanelle enzyme re sembles chloroplast DNA polymerases which are eukaryotic gamma-type en zymes. (C) 1997 Federation of European Biochemical Societies.