7xut

Structural highlights

Disease

WRN_HUMAN Defects in WRN are a cause of Werner syndrome (WRN) [MIM:277700. WRN is a rare autosomal recessive progeroid syndrome characterized by the premature onset of multiple age-related disorders, including atherosclerosis, cancer, non-insulin-dependent diabetes mellitus, ocular cataracts and osteoporosis. The major cause of death, at a median age of 47, is myocardial infarction. Currently all known WS mutations produces prematurely terminated proteins.^[1] Defects in WRN may be a cause of colorectal cancer (CRC) [MIM:114500.

Function

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.^{[2] [3]} 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.^{[4] [5]} WRN_HUMAN Multifunctional enzyme that has both magnesium and ATP-dependent DNA-helicase activity and 3'->5' exonuclease activity towards double-stranded DNA with a 5'-overhang. Has no nuclease activity towards single-stranded DNA or blunt-ended double-stranded DNA. Binds preferentially to DNA substrates containing alternate secondary structures, such as replication forks and Holliday junctions. May play an important role in the dissociation of joint DNA molecules that can arise as products of homologous recombination, at stalled replication forks or during DNA repair. Alleviates stalling of DNA polymerases at the site of DNA lesions. Important for genomic integrity. Plays a role in the formation of DNA replication focal centers; stably associates with foci elements generating binding sites for RP-A (By similarity).^{[6] [7] [8] [9] [10]}

See Also

• Single-stranded DNA-binding protein 3D structures

References

1. ↑ Huang S, Lee L, Hanson NB, Lenaerts C, Hoehn H, Poot M, Rubin CD, Chen DF, Yang CC, Juch H, Dorn T, Spiegel R, Oral EA, Abid M, Battisti C, Lucci-Cordisco E, Neri G, Steed EH, Kidd A, Isley W, Showalter D, Vittone JL, Konstantinow A, Ring J, Meyer P, Wenger SL, von Herbay A, Wollina U, Schuelke M, Huizenga CR, Leistritz DF, Martin GM, Mian IS, Oshima J. The spectrum of WRN mutations in Werner syndrome patients. Hum Mutat. 2006 Jun;27(6):558-67. PMID:16673358 doi:10.1002/humu.20337
2. ↑ 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
3. ↑ 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
4. ↑ 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
5. ↑ 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
6. ↑ Xue Y, Ratcliff GC, Wang H, Davis-Searles PR, Gray MD, Erie DA, Redinbo MR. A minimal exonuclease domain of WRN forms a hexamer on DNA and possesses both 3'- 5' exonuclease and 5'-protruding strand endonuclease activities. Biochemistry. 2002 Mar 5;41(9):2901-12. PMID:11863428
7. ↑ Kamath-Loeb AS, Lan L, Nakajima S, Yasui A, Loeb LA. Werner syndrome protein interacts functionally with translesion DNA polymerases. Proc Natl Acad Sci U S A. 2007 Jun 19;104(25):10394-9. Epub 2007 Jun 11. PMID:17563354 doi:10.1073/pnas.0702513104
8. ↑ Compton SA, Tolun G, Kamath-Loeb AS, Loeb LA, Griffith JD. The Werner syndrome protein binds replication fork and holliday junction DNAs as an oligomer. J Biol Chem. 2008 Sep 5;283(36):24478-83. doi: 10.1074/jbc.M803370200. Epub 2008 , Jul 2. PMID:18596042 doi:10.1074/jbc.M803370200
9. ↑ Zecevic A, Menard H, Gurel V, Hagan E, DeCaro R, Zhitkovich A. WRN helicase promotes repair of DNA double-strand breaks caused by aberrant mismatch repair of chromium-DNA adducts. Cell Cycle. 2009 Sep 1;8(17):2769-78. Epub 2009 Sep 2. PMID:19652551
10. ↑ Opresko PL, Sowd G, Wang H. The Werner syndrome helicase/exonuclease processes mobile D-loops through branch migration and degradation. PLoS One. 2009;4(3):e4825. doi: 10.1371/journal.pone.0004825. Epub 2009 Mar 13. PMID:19283071 doi:10.1371/journal.pone.0004825