TY - JOUR
T1 - Human flap endonuclease structures, DNA double-base flipping, and a unified understanding of the FEN1 superfamily
AU - Tsutakawa, Susan E.
AU - Classen, Scott
AU - Chapados, Brian R.
AU - Arvai, Andrew S.
AU - Finger, L. David
AU - Guenther, Grant
AU - Tomlinson, Christopher G.
AU - Thompson, Peter
AU - Sarker, Altaf H.
AU - Shen, Binghui
AU - Cooper, Priscilla K.
AU - Grasby, Jane A.
AU - Tainer, John A.
N1 - Funding Information:
Work on FEN1 is supported by the NIH/NCI through RO1CA081967, R01CA073764, and P01 CA092584 (SBDR) and by BBSRC (BBF0147321). Crystal data was collected at the SIBYLS beamline 12.3.1 (ALS, Contract DE-AC02-05CH11231) and beamline 11-1 (SSRL, supported by DOE, OBER, NIH, NCRR, Biomedical Technology Program, and the NIGMS). Morphing movies were produced with CHIMERA (NIH P41 RR-01081). We thank Hong Xu and Chiharu Hitomi for technical assistance and Gareth Williams, James Holton, Mike Pique, Elizabeth Getzoff, David Moiani, Cliff Ng, and Peter Burgers for contributing to the analyses.
PY - 2011/4/15
Y1 - 2011/4/15
N2 - Flap endonuclease (FEN1), essential for DNA replication and repair, removes RNA and DNA 5′ flaps. FEN1 5′ nuclease superfamily members acting in nucleotide excision repair (XPG), mismatch repair (EXO1), and homologous recombination (GEN1) paradoxically incise structurally distinct bubbles, ends, or Holliday junctions, respectively. Here, structural and functional analyses of human FEN1:DNA complexes show structure-specific, sequence-independent recognition for nicked dsDNA bent 100° with unpaired 3′ and 5′ flaps. Above the active site, a helical cap over a gateway formed by two helices enforces ssDNA threading and specificity for free 5′ ends. Crystallographic analyses of product and substrate complexes reveal that dsDNA binding and bending, the ssDNA gateway, and double-base unpairing flanking the scissile phosphate control precise flap incision by the two-metal-ion active site. Superfamily conserved motifs bind and open dsDNA; direct the target region into the helical gateway, permitting only nonbase-paired oligonucleotides active site access; and support a unified understanding of superfamily substrate specificity.
AB - Flap endonuclease (FEN1), essential for DNA replication and repair, removes RNA and DNA 5′ flaps. FEN1 5′ nuclease superfamily members acting in nucleotide excision repair (XPG), mismatch repair (EXO1), and homologous recombination (GEN1) paradoxically incise structurally distinct bubbles, ends, or Holliday junctions, respectively. Here, structural and functional analyses of human FEN1:DNA complexes show structure-specific, sequence-independent recognition for nicked dsDNA bent 100° with unpaired 3′ and 5′ flaps. Above the active site, a helical cap over a gateway formed by two helices enforces ssDNA threading and specificity for free 5′ ends. Crystallographic analyses of product and substrate complexes reveal that dsDNA binding and bending, the ssDNA gateway, and double-base unpairing flanking the scissile phosphate control precise flap incision by the two-metal-ion active site. Superfamily conserved motifs bind and open dsDNA; direct the target region into the helical gateway, permitting only nonbase-paired oligonucleotides active site access; and support a unified understanding of superfamily substrate specificity.
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U2 - 10.1016/j.cell.2011.03.004
DO - 10.1016/j.cell.2011.03.004
M3 - Article
C2 - 21496641
AN - SCOPUS:79953894934
SN - 0092-8674
VL - 145
SP - 198
EP - 211
JO - Cell
JF - Cell
IS - 2
ER -