9F0X: Integration host factor subunit alpha

CryoEM structure of the F plasmid relaxosome in its pre-initiation state, derived from the ds-27_+143-R Locally-refined Map 3.76 A. Determined by electron microscopy at 3.78 Å resolution. Released 4 Jun 2025.

Method
Electron microscopy
Resolution
3.78 Å
Organism
Escherichia coli K-12
Chains
8
Atoms
9,423
Mol. weight
365.66 kDa
Released
4 Jun 2025

Explore 9F0X in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9F0X contains 29 α-helices and 41 β-strands across 6 chains. 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 C: 5 helices, 8 β-strands

ElementResiduesLengthSheet
β-strand311
α-helix5-1612
α-helix20-3920
β-strand44-4632
β-strand50-5232
β-strand54-5743
β-strand60-6124
α-helix711
β-strand72-7324
α-helix74-752
β-strand76-7943
β-strand82-8322
α-helix85-895
Chain D: 3 helices, 6 β-strands
ElementResiduesLengthSheet
β-strand212
α-helix3-1311
α-helix19-3820
β-strand43-4531
β-strand49-5571
β-strand60-6345
β-strand68-7145
β-strand76-8271
α-helix84-907
Chain E: 4 helices, 2 β-strands
ElementResiduesLengthSheet
β-strand13-1866
α-helix20-3213
α-helix37-5115
β-strand68-7366
α-helix76-8914
α-helix93-10715
Chain F: 4 helices, 2 β-strands
ElementResiduesLengthSheet
β-strand13-1977
α-helix23-3311
α-helix37-5115
β-strand67-7377
α-helix76-8914
α-helix93-10715
Chain G: 5 helices, 2 β-strands
ElementResiduesLengthSheet
β-strand13-1868
α-helix20-3314
α-helix37-5115
α-helix62-643
β-strand68-7368
α-helix76-8914
α-helix93-10715
Chain H: 8 helices, 21 β-strands
ElementResiduesLengthSheet
β-strand56719
β-strand568-572510
α-helix578-59316
β-strand597-601510
α-helix605-62117
β-strand629111
β-strand632-637612
α-helix647-6493
β-strand655-658412
β-strand667-675912
β-strand680-685612
β-strand690-694512
α-helix695-6973
β-strand702-709812
β-strand712111
β-strand717-720413
β-strand734-740713
β-strand744-748513
β-strand756-759413
α-helix764-7663
β-strand768112
β-strand770-772313
β-strand775-776210
β-strand787-792610
α-helix794-7963
α-helix799-8079
β-strand811-816610
α-helix822-8243
β-strand83219

Molecules and chains

MoleculeChainsTypeLengthOrganismUniProt
T-strand DNA (83-MER)ADNA170Escherichia coli K-12
R-strand DNA (83-MER)BDNA170Escherichia coli K-12
Integration host factor subunit alphaCprotein99Escherichia coli K-12P0A6X7 (AlphaFold model)
Integration host factor subunit betaDprotein94Escherichia coli K-12P0A6Y1 (AlphaFold model)
Relaxosome protein TraYE, F, Gprotein131Escherichia coli K-12P06627 (AlphaFold model)
Multifunctional conjugation protein TraIHprotein1763Escherichia coli K-12P14565 (AlphaFold model)
Sequence of entity 1 (A), FASTA
>9F0X_1 T-strand DNA (83-MER) (chains A)
CCTACAAAACGGTGTCGGCGCGTTGTTGTAGCCGCGCCGACACCGCTTTTTTAAATATCA
TAAAGAGAGTAAGAGAAACTAATTTTTCATAACACTCTATTTATAAAGAAAAATCAGCAA
AAACTTGTTTTTGCGTGGGGTGTGGTGCTTTTGGTGGTGAGAACCACCAA
Sequence of entity 2 (B), FASTA
>9F0X_2 R-strand DNA (83-MER) (chains B)
TTGGTGGTTCTCACCACCAAAAGCACCACACCCCACGCAAAAACAAGTTTTTGCTGATTT
TTCTTTATAAATAGAGTGTTATGAAAAATTAGTTTCTCTTACTCTCTTTATGATATTTAA
AAAAGCGGTGTCGGCGCGGCTACAACAACGCGCCGACACCGTTTTGTAGG
Sequence of entity 3 (C), FASTA
>9F0X_3 Integration host factor subunit alpha (chains C)
MALTKAEMSEYLFDKLGLSKRDAKELVELFFEEIRRALENGEQVKLSGFGNFDLRDKNQR
PGRNPKTGEDIPITARRVVTFRPGQKLKSRVENASPKDE
Sequence of entity 4 (D), FASTA
>9F0X_4 Integration host factor subunit beta (chains D)
MTKSELIERLATQQSHIPAKTVEDAVKEMLEHMASTLAQGERIEIRGFGSFSLHYRAPRT
GRNPKTGDKVELEGKYVPHFKPGKELRDRANIYG
Sequence of entity 5 (E, F, G), FASTA
>9F0X_5 Relaxosome protein TraY (chains E, F, G)
MKRFGTRSATGKMVKLKLPVDVESLLIEASNRSGRSRSFEAVIRLKDHLHRYPKFNRAGN
IYGKSLVKYLTMRLDDETNQLLIAAKNRSGWCKTDEAADRVIDHLIKFPDFYNSEIFREA
DKEEDITFNTL
Sequence of entity 6 (H), FASTA
>9F0X_6 Multifunctional conjugation protein TraI (chains H)
MEFELGTMMSIAQVRSAGSAGNFYTDKDNYYVLGSMGERWAGRGAEQLGLQGSVDKDVFT
RLLEGRLPDGADLSRMQDGSNRHRPGYDLTFSAPKSVSMMAMLGGDKRLIDAHNQAVDFA
VRQVEALASTRVMTDGQSETVLTGNLVMALFNHDTSRDQEPQLHTHAVVANVTQHNGEWK
TLSSDKVGKTGFIENVYANQIAFGRLYREKLKEQVEALGYETEVVGKHGMWEMPGVPVEA
FSGRSQTIREAVGEDASLKSRDVAALDTRKSKQHVDPEIKMAEWMQTLKETGFDIRAYRD
AADQRADLRTLTPGPASQDGPDVQQAVTQAIAGLSERKVQFTYTDVLARTVGILPPENGV
IERARAGIDEAISREQLIPLDREKGLFTSGIHVLDELSVRALSRDIMKQNRVTVHPEKSV
PRTAGYSDAVSVLAQDRPSLAIVSGQGGAAGQRERVAELVMMAREQGREVQIIAADRRSQ
MNMKQDERLSGELITGRRQLLEGMAFTPGSTVIVDQGEKLSLKETLTLLDGAARHNVQVL
ITDSGQRTGTGSALMAMKDAGVNTYRWQGGEQRPATIISEPDRNVRYARLAGDFAASVKA
GEESVAQVSGVREQAILTQAIRSELKTQGVLGLPEVTMTALSPVWLDSRSRYLRDMYRPG
MVMEQWNPETRSHDRYVIDRVTAQSHSLTLRDAQGETQVVRISSLDSSWSLFRPEKMPVA
DGERLRVTGKIPGLRVSGGDRLQVASVSEDAMTVVVPGRAEPATLPVSDSPFTALKLENG
WVETPGHSVSDSATVFASVTQMAMDNATLNGLARSGRDVRLYSSLDETRTAEKLARHPSF
TVVSEQIKTRAGETSLETAISHQKSALHTPAQQAIHLALPVVESKKLAFSMVDLLTEAKS
FAAEGTGFTELGGEINAQIKRGDLLYVDVAKGYGTGLLVSRASYEAEKSILRHILEGKEA
VMPLMERVPGELMEKLTSGQRAATRMILETSDRFTVVQGYAGVGKTTQFRAVMSAVNMLP
ESERPRVVGLGPTHRAVGEMRSAGVDAQTLASFLHDTQLQQRSGETPDFSNTLFLLDESS
MVGNTDMARAYALIAAGGGRAVASGDTDQLQAIAPGQPFRLQQTRSAADVAIMKEIVRQT
PELREAVYSLINRDVERALSGLESVKPSQVPRQEGAWAPEHSVTEFSHSQEAKLAEAQQK
AMLKGEAFPDVPMTLYEAIVRDYTGRTPEAREQTLIVTHLNEDRRVLNSMIHDVREKAGE
LGKEQVMVPVLNTANIRDGELRRLSTWETHRDALVLVDNVYHRIAGISKDDGLITLQDAE
GNTRLISPREAVAEGVTLYTPDTIRVGTGDRMRFTKSDRERGYVANSVWTVTAVSGDSVT
LSDGQQTREIRPGQEQAEQHIDLAYAITAHGAQGASETFAIALEGTEGNRKLMAGFESAY
VALSRMKQHVQVYTDNRQGWTDAINNAVQKGTAHDVFEPKPDREVMNAERLFSTARELRD
VAAGRAVLRQAGLAGGDSPARFIAPGRKYPQPYVALPAFDRNGKSAGIWLNPLTTDDGNG
LRGFSGEGRVKGSGDAQFVALQGSRNGESLLADNMQDGVRIARDNPDSGVVVRIAGEGRP
WNPGAITGGRVWGDIPDNSVQPGAGNGEPVTAEVLAQRQAEEAIRRETERRADEIVRKMA
ENKPDLPDGKTEQAVREIAGQERDRAAITEREAALPEGVLREPQRVREAVREIARENLLQ
ERLQQMERDMVRDLQKEKTLGGD

Primary citation

Cryo-EM Structure of the relaxosome, a complex essential for bacterial mating and the spread of antibiotic resistance genes. Williams, S.M., Raffl, S., Kienesberger, S. et al. Nat Commun (2025) 16:4906-4906. DOI 10.1038/s41467-025-60116-6 · PubMed

Other PDB entries of the same protein (UniProt P0A6X7 (AlphaFold model), which also has an AlphaFold model), best resolution first:

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