We purified to near homogeneity a previously identified 100 kDa mammalian homologous DNA pairing protein. The purified 100 kDa protein also catalyzed high levels of cell-free homologous DNA recombination activity. This ATP-dependent activity was capable of forming conservative recombinant products between two circular, double-stranded DNA molecules. We were unable to detect any DNA polymerase, DNA ligase, or 5′ or 3′ exonuclease activity associated with this purified material. The purified 100 kDa protein bound silver nitrate as well as a monoclonal antibody specific for nucleolin. A recombinant protein comprised of the Escherichia coli maltose-binding protein fused to the carboxyl-terminal two-thirds of human nucleolin possessed homologous DNA pairing activity. These data indicate that the 100 kDa homologous DNA pairing protein is nucleolin. The observation that nucleolin can carry out homologous DNA strand pairing in vitro raises the prospect that it may function similarly in vivo.
|Original language||English (US)|
|Number of pages||10|
|Journal||Somatic Cell and Molecular Genetics|
|State||Published - 1998|
Bibliographical noteFunding Information:
This work was supported by grants from the National Institute of Health (CA R29 CA61906), the American Heart Association (9601390), and the American Cancer Society (DHP-171). Support was also received from the H. Louise Ruddell Charitable Trust.