9XZM: F-box helicase 1

Cryo-EM structure of F-box helicase 1 (FBH1) bound to an SCF ubiquitin ligase complex and a 3-way DNA fork (substrate structure). Determined by electron microscopy at 10.27 Å resolution. Released 28 Jan 2026.

Method
Electron microscopy
Resolution
10.27 Å
Organisms
synthetic construct, Homo sapiens
Chains
5
Atoms
7,341
Mol. weight
150.02 kDa
Ligands
ZN, MG, AGS
Released
28 Jan 2026

Explore 9XZM in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9XZM contains 44 α-helices and 26 β-strands across 1 chain. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chain F: 44 helices, 26 β-strands

ElementResiduesLengthSheet
α-helix369-3768
β-strand384-38961
α-helix395-40511
β-strand411-41551
α-helix418-42710
β-strand432-43651
α-helix437-4415
α-helix442-4465
α-helix447-4515
β-strand45512
α-helix462-4687
α-helix4701
α-helix476-49116
α-helix499-5013
β-strand505-50733
β-strand513-51533
α-helix516-5172
α-helix518-53619
α-helix544-5463
β-strand54812
α-helix550-55910
β-strand569-57351
α-helix575-5773
α-helix580-5878
β-strand592-59761
α-helix599-6013
α-helix605-6073
α-helix612-6154
β-strand620-62451
β-strand62614
α-helix632-64615
β-strand65414
β-strand66115
β-strand670-67455
α-helix677-68812
α-helix693-6953
β-strand696-69835
α-helix703-7053
α-helix707-71711
α-helix720-7267
α-helix733-7375
α-helix744-75411
α-helix757-76913
α-helix770-7723
α-helix773-78311
β-strand78415
α-helix788-7903
β-strand793-79755
α-helix798-8014
β-strand806-81165
α-helix816-8183
α-helix822-8276
α-helix833-8353
α-helix838-84912
β-strand851-85665
α-helix859-8679
β-strand873-87756
α-helix878-8814
β-strand88817
α-helix8961
β-strand89717
α-helix898-8992
β-strand904-90856
α-helix909-9102
β-strand911-91228
β-strand918-91928
β-strand922-92436
α-helix926-9338
α-helix934-9396
α-helix943-9475

Molecules and chains

MoleculeChainsTypeLengthOrganismUniProt
DNA (45-mer)XDNA45synthetic construct
DNA (5'-d(*tp*cp*gp*cp*tp*ap*cp*cp*tp*tp*cp*gp*cp*ap*gp*tp*c)-3')BDNA17synthetic construct
DNA (45-mer)YDNA45synthetic construct
DNA (5'-d(*cp*tp*gp*ap*cp*gp*cp*tp*tp*cp*cp*ap*tp*cp*gp*cp*tp*gp*tp*cp*tp*ap*g)-3')ADNA23synthetic construct
F-box DNA helicase 1Fprotein972Homo sapiensQ8NFZ0 (AlphaFold model)
Sequence of entity 1 (X), FASTA
>9XZM_1 DNA (45-MER) (chains X)
GACTGCGAAGGTAGCGACAGATCCCCTGACGAACTGAGTCCTGAG
Sequence of entity 2 (B), FASTA
>9XZM_2 DNA (5'-D(*TP*CP*GP*CP*TP*AP*CP*CP*TP*TP*CP*GP*CP*AP*GP*TP*C)-3') (chains B)
TCGCTACCTTCGCAGTC
Sequence of entity 3 (Y), FASTA
>9XZM_3 DNA (45-MER) (chains Y)
CTCAGGACTCAGTTCGTCAGCCCTAGACAGCGATGGAAGCGTCAG
Sequence of entity 4 (A), FASTA
>9XZM_4 DNA (5'-D(*CP*TP*GP*AP*CP*GP*CP*TP*TP*CP*CP*AP*TP*CP*GP*CP*TP*GP*TP*CP*TP*AP*G)-3') (chains A)
CTGACGCTTCCATCGCTGTCTAG
Sequence of entity 5 (F), FASTA
>9XZM_5 F-box DNA helicase 1 (chains F)
SNAMAKSNSVGQDSCQDSEGDMIFPAESSCALPQEGSAGPGSPGSAPPSRKRSWSSEEES
NQATGTSRWDGVSKKAPRHHLSVPCTRPREARQEAEDSTSRLSAESGETDQDAGDVGPDP
IPDSYYGLLGTLPCQEALSHICSLPSEVLRHVFAFLPVEDLYWNLSLVCHLWREIISDPL
FIPWKKLYHRYLMNEEQAVSKVDGILSNCGIEKESDLCVLNLIRYTATTKCSPSVDPERV
LWSLRDHPLLPEAEACVRQHLPDLYAAAGGVNIWALVAAVVLLSSSVNDIQRLLFCLRRP
SSTVTMPDVTETLYCIAVLLYAMREKGINISNRIHYNIFYCLYLQENSCTQATKVKEEPS
VWPGKKTIQLTHEQQLILNHKMEPLQVVKIMAFAGTGKTSTLVKYAEKWSQSRFLYVTFN
KSIAKQAERVFPSNVICKTFHSMAYGHIGRKYQSKKKLNLFKLTPFMVNSVLAEGKGGFI
RAKLVCKTLENFFASADEELTIDHVPIWCKNSQGQRVMVEQSEKLNGVLEASRLWDNMRK
LGECTEEAHQMTHDGYLKLWQLSKPSLASFDAIFVDEAQDCTPAIMNIVLSQPCGKIFVG
DPHQQIYTFRGAVNALFTVPHTHVFYLTQSFRFGVEIAYVGATILDVCKRVRKKTLVGGN
HQSGIRGDAKGQVALLSRTNANVFDEAVRVTEGEFPSRIHLIGGIKSFGLDRIIDIWILL
QPEEERRKQNLVIKDKFIRRWVHKEGFSGFKRYVTAAEDKELEAKIAVVEKYNIRIPELV
QRIEKCHIEDLDFAEYILGTVHKAKGLEFDTVHVLDDFVKVPCARHNLPQLPHFRVESFS
EDEWNLLYVAVTRAKKRLIMTKSLENILTLAGEYFLQAELTSNVLKTGVVRCCVGQCNNA
IPVDTVLTMKKLPITYSNRKENKGGYLCHSCAEQRIGPLAFLTASPEQVRAMERTVENIV
LPRHEALLFLVF

Ligands and cofactors

IDNameFormulaCopies
ZNZinc ionZn1
MGMagnesium ionMg1
AGSPhosphothiophosphoric acid-adenylate esterC10 H16 N5 O12 P3 S1

Primary citation

Structural basis for fork reversal and RAD51 regulation by the SCF ubiquitin ligase complex of F-box helicase 1. Greer, B.H., Mendia-Garcia, J., Mullins, E.A. et al. Nat Commun (2026) 17. DOI 10.1038/s41467-026-68752-2 · PubMed

Other PDB entries of the same protein (UniProt Q8NFZ0 (AlphaFold model), which also has an AlphaFold model), best resolution first:

Browse structure collections

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