9K4R: 26S proteasome regulatory subunit 7

Structure of substrate-engaged human 26S proteasome RP-CP subcomplex in state EB.1. Determined by electron microscopy at 3.1 Å resolution. Released 29 Apr 2026.

Method
Electron microscopy
Resolution
3.1 Å
Organisms
Homo sapiens, Saccharomyces cerevisiae
Chains
48
Atoms
106,266
Mol. weight
1677.37 kDa
Ligands
ATP, MG, ADP, ZN
Released
29 Apr 2026

Explore 9K4R in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9K4R contains 603 α-helices and 541 β-strands across 48 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 a: 23 helices, 5 β-strands

ElementResiduesLengthSheet
α-helix5-128
α-helix18-258
α-helix36-4510
α-helix54-6613
α-helix73-8715
α-helix91-10313
α-helix111-12111
α-helix134-1418
α-helix150-16213
α-helix170-18112
α-helix190-20516
α-helix215-2184
α-helix223-2286
α-helix232-24110
α-helix249-2568
α-helix265-2739
α-helix277-2804
β-strand290-29234
α-helix293-2997
α-helix304-3063
α-helix307-31711
β-strand32015
β-strand323-32534
β-strand330-33234
β-strand33615
α-helix337-3404
α-helix343-37028
α-helix372-3754
Chain A: 16 helices, 12 β-strands
ElementResiduesLengthSheet
α-helix28-369
α-helix43-6220
α-helix84-907
β-strand97-10371
β-strand111-11441
β-strand120-12561
β-strand139-14241
β-strand148-15251
α-helix159-1624
β-strand16512
α-helix174-1774
α-helix181-19111
α-helix193-1964
α-helix200-2045
β-strand211-21552
α-helix224-2318
β-strand237-24152
β-strand24913
α-helix252-26615
β-strand270-27562
α-helix294-30613
β-strand315-32172
α-helix329-3324
β-strand339-34242
α-helix350-35910
α-helix371-3766
α-helix382-39817
α-helix406-42116
Chain b: 9 helices, 7 β-strands
ElementResiduesLengthSheet
β-strand4-9611
α-helix14-174
α-helix25-4319
β-strand49-52411
β-strand60111
β-strand65111
α-helix69-757
α-helix91-944
α-helix97-993
β-strand106-113811
α-helix121-13111
α-helix132-1343
β-strand137-142611
α-helix154-1607
β-strand169-171311
α-helix180-1834
Chain B: 19 helices, 14 β-strands
ElementResiduesLengthSheet
α-helix59-8527
α-helix94-1029
β-strand107-10936
β-strand115-11627
β-strand120-12457
β-strand130-13457
β-strand13518
α-helix141-1433
β-strand150-15236
β-strand15918
β-strand161-16226
α-helix169-1746
α-helix184-1863
α-helix193-1975
α-helix198-2025
α-helix203-2064
α-helix210-2145
α-helix217-2193
β-strand221-22559
α-helix232-24110
β-strand247-25159
α-helix252-2543
β-strand259110
α-helix263-27715
β-strand281-28559
α-helix302-31615
β-strand326-33059
α-helix339-3424
β-strand349-35249
α-helix361-3688
α-helix381-3844
α-helix392-40817
α-helix416-43116
Chain c: 12 helices, 10 β-strands
ElementResiduesLengthSheet
β-strand30-33413
α-helix35-4713
β-strand56-61613
β-strand66-73813
β-strand77-79314
β-strand84-86314
α-helix90-10011
β-strand107-114813
α-helix124-13613
β-strand141-145513
β-strand157-162613
α-helix165-1673
α-helix186-1883
α-helix189-1924
β-strand200-203413
β-strand205-207313
α-helix211-2188
α-helix225-2295
α-helix236-26126
α-helix267-2693
α-helix270-2734
α-helix283-30826
Chain C: 23 helices, 12 β-strands
ElementResiduesLengthSheet
α-helix21-6545
β-strand71-7551
β-strand7616
β-strand8016
β-strand84-8746
β-strand95-9846
β-strand113-11751
β-strand123-12641
α-helix127-1293
α-helix133-1364
α-helix138-1403
α-helix155-1617
α-helix162-1665
α-helix167-1704
α-helix172-1787
α-helix181-1833
β-strand185-189512
α-helix197-20610
β-strand210-213412
α-helix219-2224
α-helix227-2293
α-helix232-24110
β-strand244-247412
α-helix251-2555
α-helix259-2613
α-helix270-28213
β-strand290-294512
α-helix298-3003
β-strand314-316312
α-helix318-3203
α-helix322-33211
α-helix338-3392
α-helix344-3496
α-helix356-37217
α-helix380-39314
Chain d: 11 helices, 0 β-strands
ElementResiduesLengthSheet
α-helix17-3014
α-helix44-6522
α-helix68-8215
α-helix94-10714
α-helix112-1198
α-helix131-14111
α-helix148-1525
α-helix164-18320
α-helix191-1944
α-helix205-2128
α-helix238-25417
Chain D: 16 helices, 11 β-strands
ElementResiduesLengthSheet
α-helix40-7940
α-helix80-823
β-strand87-9481
β-strand100-10561
β-strand110-11451
α-helix121-1233
β-strand129-13241
β-strand139-14241
α-helix156-1583
α-helix171-1788
α-helix183-1864
α-helix189-1946
β-strand201-205515
α-helix212-2198
β-strand226-230515
α-helix242-25716
β-strand260-265615
α-helix267-2693
α-helix282-29716
β-strand305-310615
β-strand327-332615
α-helix334-3363
α-helix338-34811
α-helix360-3656
α-helix374-38815
β-strand391116
α-helix396-40611

40 more chain groups are not listed. Open the entry in the viewer and use the sequence panel to see them.

Molecules and chains

MoleculeChainsTypeLengthOrganismUniProt
26S proteasome regulatory subunit 7Aprotein433Homo sapiensP35998 (AlphaFold model)
26S proteasome regulatory subunit 4Bprotein440Homo sapiensP62191 (AlphaFold model)
26S proteasome regulatory subunit 8Cprotein398Homo sapiensP62195 (AlphaFold model)
26S proteasome regulatory subunit 6BDprotein418Homo sapiensP43686 (AlphaFold model)
Proteasome 26S subunit, ATPase 6Eprotein403Homo sapiensA0A087X2I1
26S proteasome regulatory subunit 6AFprotein439Homo sapiensP17980
Proteasome subunit alpha type-6G, gprotein246Homo sapiensP60900
Proteasome subunit alpha type-2H, hprotein234Homo sapiensP25787
Proteasome subunit alpha type-4I, iprotein261Homo sapiensP25789
Proteasome subunit alpha type-7J, jprotein248Homo sapiensO14818
Proteasome subunit alpha type-5K, kprotein241Homo sapiensP28066
Proteasome subunit alpha type-1L, lprotein263Homo sapiensP25786

22 more molecules are not listed.

Sequence of entity 1 (A), FASTA
>9K4R_1 26S proteasome regulatory subunit 7 (chains A)
MPDYLGADQRKTKEDEKDDKPIRALDEGDIALLKTYGQSTYSRQIKQVEDDIQQLLKKIN
ELTGIKESDTGLAPPALWDLAADKQTLQSEQPLQVARCTKIINADSEDPKYIINVKQFAK
FVVDLSDQVAPTDIEEGMRVGVDRNKYQIHIPLPPKIDPTVTMMQVEEKPDVTYSDVGGC
KEQIEKLREVVETPLLHPERFVNLGIEPPKGVLLFGPPGTGKTLCARAVANRTDACFIRV
IGSELVQKYVGEGARMVRELFEMARTKKACLIFFDEIDAIGGARFDDGAGGDNEVQRTML
ELINQLDGFDPRGNIKVLMATNRPDTLDPALMRPGRLDRKIEFSLPDLEGRTHIFKIHAR
SMSVERDIRFELLARLCPNSTGAEIRSVCTEAGMFAIRARRKIATEKDFLEAVNKVIKSY
AKFSATPRYMTYN
Sequence of entity 2 (B), FASTA
>9K4R_2 26S proteasome regulatory subunit 4 (chains B)
MGQSQSGGHGPGGGKKDDKDKKKKYEPPVPTRVGKKKKKTKGPDAASKLPLVTPHTQCRL
KLLKLERIKDYLLMEEEFIRNQEQMKPLEEKQEEERSKVDDLRGTPMSVGTLEEIIDDNH
AIVSTSVGSEHYVSILSFVDKDLLEPGCSVLLNHKVHAVIGVLMDDTDPLVTVMKVEKAP
QETYADIGGLDNQIQEIKESVELPLTHPEYYEEMGIKPPKGVILYGPPGTGKTLLAKAVA
NQTSATFLRVVGSELIQKYLGDGPKLVRELFRVAEEHAPSIVFIDEIDAIGTKRYDSNSG
GEREIQRTMLELLNQLDGFDSRGDVKVIMATNRIETLDPALIRPGRIDRKIEFPLPDEKT
KKRIFQIHTSRMTLADDVTLDDLIMAKDDLSGADIKAICTEAGLMALRERRMKVTNEDFK
KSKENVLYKKQEGTPEGLYL
Sequence of entity 3 (C), FASTA
>9K4R_3 26S proteasome regulatory subunit 8 (chains C)
MELEEGKAGSGLRQYYLSKIEELQLIVNDKSQNLRRLQAQRNELNAKVRLLREELQLLQE
QGSYVGEVVRAMDKKKVLVKVHPEGKFVVDVDKNIDINDVTPNCRVALRNDSYTLHKILP
NKVDPLVSLMMVEKVPDSTYEMIGGLDKQIKEIKEVIELPVKHPELFEALGIAQPKGVLL
YGPPGTGKTLLARAVAHHTDCTFIRVSGSELVQKFIGEGARMVRELFVMAREHAPSIIFM
DEIDSIGSSRLEGGSGGDSEVQRTMLELLNQLDGFEATKNIKVIMATNRIDILDSALLRP
GRIDRKIEFPPPNEEARLDILKIHSRKMNLTRGINLRKIAELMPGASGAEVKGVCTEAGM
YALRERRVHVTQEDFEMAVAKVMQKDSEKNMSIKKLWK
Sequence of entity 4 (D), FASTA
>9K4R_4 26S proteasome regulatory subunit 6B (chains D)
MEEIGILVEKAQDEIPALSVSRPQTGLSFLGPEPEDLEDLYSRYKKLQQELEFLEVQEEY
IKDEQKNLKKEFLHAQEEVKRIQSIPLVIGQFLEAVDQNTAIVGSTTGSNYYVRILSTID
RELLKPNASVALHKHSNALVDVLPPEADSSIMMLTSDQKPDVMYADIGGMDIQKQEVREA
VELPLTHFELYKQIGIDPPRGVLMYGPPGCGKTMLAKAVAHHTTAAFIRVVGSEFVQKYL
GEGPRMVRDVFRLAKENAPAIIFIDEIDAIATKRFDAQTGADREVQRILLELLNQMDGFD
QNVNVKVIMATNRADTLDPALLRPGRLDRKIEFPLPDRRQKRLIFSTITSKMNLSEEVDL
EDYVARPDKISGADINSICQESGMLAVRENRYIVLAKDFEKAYKTVIKKDEQEHEFYK
Sequence of entity 5 (E), FASTA
>9K4R_5 Proteasome 26S subunit, ATPase 6 (chains E)
MAIPGIPYERRLLIMADPRDKALQDYRKKLLEHKEIDGRLKELREQLKELTKQYEKSEND
LKALQSVGQIVGEVLKQLTEEKFIVKATNGPRYVVGCRRQLDKSKLKPGTRVALDMTTLT
IMRYLPREVDPLVYNMSHEDPGNVSYSEIGGLSEQIRELREVIELPLTNPELFQRVGIIP
PKGCLLYGPPGTGKTLLARAVASQLDCNFLKVVSSSIVDKYIGESARLIREMFNYARDHQ
PCIIFMDEIDAIGGRRFSEGTSADREIQRTLMELLNQMDGFDTLHRVKMIMATNRPDTLD
PALLRPGRLDRKIHIDLPNEQARLDILKIHAGPITKHGEIDYEAIVKLSDGFNGADLRNV
CTEAGMFAIRADHDFVVQEDFMKAVRKVADSKKLESKLDYKPV
Sequence of entity 6 (F), FASTA
>9K4R_6 26S proteasome regulatory subunit 6A (chains F)
MNLLPNIESPVTRQEKMATVWDEAEQDGIGEEVLKMSTEEIIQRTRLLDSEIKIMKSEVL
RVTHELQAMKDKIKENSEKIKVNKTLPYLVSNVIELLDVDPNDQEEDGANIDLDSQRKGK
CAVIKTSTRQTYFLPVIGLVDAEKLKPGDLVGVNKDSYLILETLPTEYDSRVKAMEVDER
PTEQYSDIGGLDKQIQELVEAIVLPMNHKEKFENLGIQPPKGVLMYGPPGTGKTLLARAC
AAQTKATFLKLAGPQLVQMFIGDGAKLVRDAFALAKEKAPSIIFIDELDAIGTKRFDSEK
AGDREVQRTMLELLNQLDGFQPNTQVKVIAATNRVDILDPALLRSGRLDRKIEFPMPNEE
ARARIMQIHSRKMNVSPDVNYEELARCTDDFNGAQCKAVCVEAGMIALRRGATELTHEDY
MEGILEVQAKKKANLQYYA
Sequence of entity 7 (G, g), FASTA
>9K4R_7 Proteasome subunit alpha type-6 (chains G, g)
MSRGSSAGFDRHITIFSPEGRLYQVEYAFKAINQGGLTSVAVRGKDCAVIVTQKKVPDKL
LDSSTVTHLFKITENIGCVMTGMTADSRSQVQRARYEAANWKYKYGYEIPVDMLCKRIAD
ISQVYTQNAEMRPLGCCMILIGIDEEQGPQVYKCDPAGYYCGFKATAAGVKQTESTSFLE
KKVKKKFDWTFEQTVETAITCLSTVLSIDFKPSEIEVGVVTVENPKFRILTEAEIDAHLV
ALAERD
Sequence of entity 8 (H, h), FASTA
>9K4R_8 Proteasome subunit alpha type-2 (chains H, h)
MAERGYSFSLTTFSPSGKLVQIEYALAAVAGGAPSVGIKAANGVVLATEKKQKSILYDER
SVHKVEPITKHIGLVYSGMGPDYRVLVHRARKLAQQYYLVYQEPIPTAQLVQRVASVMQE
YTQSGGVRPFGVSLLICGWNEGRPYLFQSDPSGAYFAWKATAMGKNYVNGKTFLEKRYNE
DLELEDAIHTAILTLKESFEGQMTEDNIEVGICNEAGFRRLTPTEVKDYLAAIA
Sequence of entity 9 (I, i), FASTA
>9K4R_9 Proteasome subunit alpha type-4 (chains I, i)
MSRRYDSRTTIFSPEGRLYQVEYAMEAIGHAGTCLGILANDGVLLAAERRNIHKLLDEVF
FSEKIYKLNEDMACSVAGITSDANVLTNELRLIAQRYLLQYQEPIPCEQLVTALCDIKQA
YTQFGGKRPFGVSLLYIGWDKHYGFQLYQSDPSGNYGGWKATCIGNNSAAAVSMLKQDYK
EGEMTLKSALALAIKVLNKTMDVSKLSAEKVEIATLTRENGKTVIRVLKQKEVEQLIKKH
EEEEAKAEREKKEKEQKEKDK
Sequence of entity 10 (J, j), FASTA
>9K4R_10 Proteasome subunit alpha type-7 (chains J, j)
MSYDRAITVFSPDGHLFQVEYAQEAVKKGSTAVGVRGRDIVVLGVEKKSVAKLQDERTVR
KICALDDNVCMAFAGLTADARIVINRARVECQSHRLTVEDPVTVEYITRYIASLKQRYTQ
SNGRRPFGISALIVGFDFDGTPRLYQTDPSGTYHAWKANAIGRGAKSVREFLEKNYTDEA
IETDDLTIKLVIKALLEVVQSGGKNIELAVMRRDQSLKILNPEEIEKYVAEIEKEKEENE
KKKQKKAS
Sequence of entity 11 (K, k), FASTA
>9K4R_11 Proteasome subunit alpha type-5 (chains K, k)
MFLTRSEYDRGVNTFSPEGRLFQVEYAIEAIKLGSTAIGIQTSEGVCLAVEKRITSPLME
PSSIEKIVEIDAHIGCAMSGLIADAKTLIDKARVETQNHWFTYNETMTVESVTQAVSNLA
LQFGEEDADPGAMSRPFGVALLFGGVDEKGPQLFHMDPSGTFVQCDARAIGSASEGAQSS
LQEVYHKSMTLKEAIKSSLIILKQVMEEKLNATNIELATVQPGQNFHMFTKEELEEVIKD
I
Sequence of entity 12 (L, l), FASTA
>9K4R_12 Proteasome subunit alpha type-1 (chains L, l)
MFRNQYDNDVTVWSPQGRIHQIEYAMEAVKQGSATVGLKSKTHAVLVALKRAQSELAAHQ
KKILHVDNHIGISIAGLTADARLLCNFMRQECLDSRFVFDRPLPVSRLVSLIGSKTQIPT
QRYGRRPYGVGLLIAGYDDMGPHIFQTCPSANYFDCRAMSIGARSQSARTYLERHMSEFM
ECNLNELVKHGLRALRETLPAEQDLTTKNVSIGIVGKDLEFTIYDDDDVSPFLEGLEERP
QRKAQPAQPADEPAEKADEPMEH

Ligands and cofactors

IDNameFormulaCopies
ATPAdenosine-5'-triphosphateC10 H16 N5 O13 P33
MGMagnesium ionMg3
ADPAdenosine-5'-diphosphateC10 H15 N5 O10 P22
ZNZinc ionZn1

Primary citation

Hidden dynamics of ubiquitin-mediated proteasome autoregulation during protein degradation. Wu, Z., Chen, E., Zou, S. et al. To be published.

Other PDB entries of the same protein (UniProt P35998 (AlphaFold model), which also has an AlphaFold model), best resolution first:

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