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Structural highlights

Disease

BLM_HUMAN Bloom syndrome. The disease is caused by mutations affecting the gene represented in this entry.

Function

BLM_HUMAN Participates in DNA replication and repair. Exhibits a magnesium-dependent ATP-dependent DNA-helicase activity that unwinds single- and double-stranded DNA in a 3'-5' direction. Involved in 5'-end resection of DNA during double-strand break (DSB) repair: unwinds DNA and recruits DNA2 which mediates the cleavage of 5'-ssDNA. Negatively regulates sister chromatid exchange (SCE).^{[1] [2] [3] [4]} RFA1_HUMAN Plays an essential role in several cellular processes in DNA metabolism including replication, recombination and DNA repair. Binds and subsequently stabilizes single-stranded DNA intermediates and thus prevents complementary DNA from reannealing.^{[5] [6]} Functions as component of the alternative replication protein A complex (aRPA). aRPA binds single-stranded DNA and probably plays a role in DNA repair; it does not support chromosomal DNA replication and cell cycle progression through S-phase. In vitro, aRPA cannot promote efficient priming by DNA polymerase alpha but supports DNA polymerase delta synthesis in the presence of PCNA and replication factor C (RFC), the dual incision/excision reaction of nucleotide excision repair and RAD51-dependent strand exchange.^{[7] [8]}

See Also

• Single-stranded DNA-binding protein 3D structures

References

1. ↑ Karow JK, Chakraverty RK, Hickson ID. The Bloom's syndrome gene product is a 3'-5' DNA helicase. J Biol Chem. 1997 Dec 5;272(49):30611-4. PMID:9388193
2. ↑ Langland G, Elliott J, Li Y, Creaney J, Dixon K, Groden J. The BLM helicase is necessary for normal DNA double-strand break repair. Cancer Res. 2002 May 15;62(10):2766-70. PMID:12019152
3. ↑ Nimonkar AV, Genschel J, Kinoshita E, Polaczek P, Campbell JL, Wyman C, Modrich P, Kowalczykowski SC. BLM-DNA2-RPA-MRN and EXO1-BLM-RPA-MRN constitute two DNA end resection machineries for human DNA break repair. Genes Dev. 2011 Feb 15;25(4):350-62. doi: 10.1101/gad.2003811. PMID:21325134 doi:http://dx.doi.org/10.1101/gad.2003811
4. ↑ Wan L, Han J, Liu T, Dong S, Xie F, Chen H, Huang J. Scaffolding protein SPIDR/KIAA0146 connects the Bloom syndrome helicase with homologous recombination repair. Proc Natl Acad Sci U S A. 2013 Jun 25;110(26):10646-51. doi:, 10.1073/pnas.1220921110. Epub 2013 Mar 18. PMID:23509288 doi:http://dx.doi.org/10.1073/pnas.1220921110
5. ↑ Mason AC, Haring SJ, Pryor JM, Staloch CA, Gan TF, Wold MS. An alternative form of replication protein a prevents viral replication in vitro. J Biol Chem. 2009 Feb 20;284(8):5324-31. doi: 10.1074/jbc.M808963200. Epub 2008, Dec 29. PMID:19116208 doi:10.1074/jbc.M808963200
6. ↑ Kemp MG, Mason AC, Carreira A, Reardon JT, Haring SJ, Borgstahl GE, Kowalczykowski SC, Sancar A, Wold MS. An alternative form of replication protein a expressed in normal human tissues supports DNA repair. J Biol Chem. 2010 Feb 12;285(7):4788-97. doi: 10.1074/jbc.M109.079418. Epub 2009 , Dec 7. PMID:19996105 doi:10.1074/jbc.M109.079418
7. ↑ Mason AC, Haring SJ, Pryor JM, Staloch CA, Gan TF, Wold MS. An alternative form of replication protein a prevents viral replication in vitro. J Biol Chem. 2009 Feb 20;284(8):5324-31. doi: 10.1074/jbc.M808963200. Epub 2008, Dec 29. PMID:19116208 doi:10.1074/jbc.M808963200
8. ↑ Kemp MG, Mason AC, Carreira A, Reardon JT, Haring SJ, Borgstahl GE, Kowalczykowski SC, Sancar A, Wold MS. An alternative form of replication protein a expressed in normal human tissues supports DNA repair. J Biol Chem. 2010 Feb 12;285(7):4788-97. doi: 10.1074/jbc.M109.079418. Epub 2009 , Dec 7. PMID:19996105 doi:10.1074/jbc.M109.079418