| First Author | Borggrefe T | Year | 1998 |
| Journal | J Biol Chem | Volume | 273 |
| Issue | 27 | Pages | 17025-35 |
| PubMed ID | 9642267 | Mgi Jnum | J:48490 |
| Mgi Id | MGI:1270060 | Doi | 10.1074/jbc.273.27.17025 |
| Citation | Borggrefe T, et al. (1998) A B-cell-specific DNA recombination complex. J Biol Chem 273(27):17025-35 |
| abstractText | We have purified and biochemically characterized a multiprotein complex designated SWAP. In a DNA transfer assay, SWAP preferentially recombines (swaps) sequences derived from Ig heavy chain switch regions. We identified four of the proteins in the SWAP complex: B23 (nucleophosmin), C23 (nucleolin), poly(ADP-ribose) polymerase (PARP), and SWAP-70. The first three are proteins known to be present in most cells. B23 promotes single-strand DNA reannealing and the formation of joint molecules in a D-loop assay between homologous, but also between Smu and Sgamma sequences. SWAP-70 is a novel protein of 70 kDa. Its cDNA was cloned and sequenced, and the protein was overexpressed in Escherichia coli. SWAP-70 protein expression was found only in B lymphocytes that had been induced to switch to various Ig isotypes and in switching B-cell lines. SWAP-70 is a nuclear protein, has a weak affinity for DNA, binds ATP, and forms specific, high affinity complexes with B23, C23, and poly(ADP-ribose) polymerase. These findings are consistent with SWAP being the long elusive switch recombinase and with SWAP-70 being the specific recruiting element that assembles the switch recombinase from universal components. |
