9RLA: 13S+Beta1 proteasome precursor complex

13S+Beta1 proteasome precursor complex. Determined by electron microscopy at 3.16 Å resolution. Released 18 Mar 2026.

Method: Electron microscopy
Resolution: 3.16 Å
Organism: Saccharomyces cerevisiae
Chains: 14
Atoms: 24,539
Mol. weight: 375.41 kDa
Released: 18 Mar 2026

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

Secondary structure: helices and β-sheets

9RLA contains 122 α-helices and 185 β-strands across 14 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 3: 8 helices, 0 β-strands

Element	Residues	Length
α-helix	-10--5	6
α-helix	32-35	4
α-helix	53-58	6
α-helix	60-76	17
α-helix	79-93	15
α-helix	105-110	6
α-helix	119-122	4
α-helix	138-146	9

Chain 4: 12 helices, 15 β-strands

Element	Residues	Length	Sheet
α-helix	9-12	4
α-helix	18-20	3
α-helix	30-32	3
β-strand	35-37	3	22
α-helix	44-46	3
β-strand	49-54	6	22
α-helix	55-60	6
α-helix	63-66	4
β-strand	69-80	12	22
α-helix	96-99	4
β-strand	103	1	5
α-helix	106-109	4
β-strand	116-127	12	22
β-strand	130-135	6	22
α-helix	144-158	15
β-strand	164-167	4	22
β-strand	170-171	2	23
β-strand	178-181	4	22
β-strand	193-194	2	24
α-helix	196-205	10
β-strand	215-218	4	22
β-strand	219-220	2	23
β-strand	222	1	25
β-strand	229	1	25
α-helix	232-246	15
α-helix	252-261	10
β-strand	275	1	17

Chain 5: 11 helices, 23 β-strands

Element	Residues	Length	Sheet
β-strand	3-7	5	26
α-helix	11-13	3
α-helix	14-25	12
β-strand	30-34	5	26
β-strand	41	1	27
β-strand	44-45	2	24
β-strand	46	1	28
β-strand	51	1	29
α-helix	55-57	3
β-strand	67	1	28
β-strand	70-75	6	26
β-strand	80-85	6	26
β-strand	89	1	27
α-helix	94-98	5
α-helix	99-103	5
α-helix	104-110	7
β-strand	114-118	5	26
β-strand	121	1	30
β-strand	131	1	31
β-strand	139-141	3	26
β-strand	144	1	26
α-helix	149-153	5
α-helix	156-158	3
β-strand	165	1	32
β-strand	176	1	31
β-strand	179	1	32
α-helix	184-193	10
β-strand	204	1	26
β-strand	207-209	3	26
β-strand	211	1	30
α-helix	220-230	11
β-strand	246	1	29
α-helix	247-251	5
β-strand	266	1	33

Chain A: 10 helices, 12 β-strands

Element	Residues	Length	Sheet
α-helix	26-33	8
α-helix	34-36	3
β-strand	43-46	4	1
β-strand	51-55	5	1
β-strand	64	1	2
α-helix	66-68	3
β-strand	72-74	3	3
β-strand	79-84	6	3
α-helix	87-108	22
α-helix	111-113	3
α-helix	114-130	17
β-strand	131	1	4
α-helix	135-137	3
β-strand	140-147	8	3
β-strand	151-157	7	3
β-strand	163-166	4	3
β-strand	168-169	2	1
α-helix	175-189	15
α-helix	199-214	16
β-strand	224-228	5	1
β-strand	233-235	3	1
α-helix	238-249	12

Chain B: 12 helices, 16 β-strands

Element	Residues	Length	Sheet
β-strand	12	1	34
β-strand	18	1	34
α-helix	19-28	10
β-strand	34-39	6	35
β-strand	42-48	7	35
β-strand	56	1	3
α-helix	58-60	3
β-strand	64-68	5	36
β-strand	71-77	7	36
α-helix	79-92	14
α-helix	93-98	6
α-helix	107-119	13
α-helix	120-123	4
β-strand	127	1	4
α-helix	128-130	3
β-strand	132-140	9	36
β-strand	144-150	7	36
β-strand	156-158	3	36
β-strand	159	1	37
β-strand	161-164	4	35
α-helix	168-178	11
α-helix	185-197	13
β-strand	209-214	6	35
α-helix	219-221	3
β-strand	224	1	38
β-strand	235-237	3	35
α-helix	238-239	2
α-helix	240-248	9

Chain C: 10 helices, 13 β-strands

Element	Residues	Length	Sheet
α-helix	20-29	10
β-strand	35-39	5	39
β-strand	43-49	7	39
β-strand	57	1	37
β-strand	66-68	3	40
β-strand	73-77	5	40
α-helix	82-102	21
α-helix	105-107	3
α-helix	108-121	14
β-strand	125	1	9
α-helix	129-131	3
β-strand	135-141	7	40
β-strand	145-151	7	40
β-strand	157-159	3	40
β-strand	160	1	7
β-strand	162-165	4	39
α-helix	169-179	11
α-helix	186-199	14
α-helix	208-210	3
β-strand	211-218	8	39
β-strand	225-229	5	39
α-helix	230-231	2
α-helix	232-242	11

Chain D: 9 helices, 14 β-strands

Element	Residues	Length	Sheet
α-helix	18-27	10
β-strand	30	1	5
β-strand	33-37	5	6
β-strand	42-47	6	6
α-helix	48-52	5
β-strand	55	1	7
β-strand	65-66	2	8
β-strand	71-77	7	8
α-helix	79-100	22
α-helix	103-105	3
α-helix	106-119	14
β-strand	126	1	9
β-strand	131-138	8	8
β-strand	145-150	6	8
β-strand	156-158	3	8
β-strand	159	1	10
β-strand	161-164	4	6
α-helix	168-178	11
α-helix	188-200	13
α-helix	207-209	3
β-strand	210-216	7	6
β-strand	220-223	4	6
α-helix	226-244	19

Chain E: 10 helices, 14 β-strands

Element	Residues	Length	Sheet
α-helix	22-31	10
β-strand	37-42	6	11
β-strand	45-50	6	11
β-strand	59	1	10
β-strand	67-71	5	12
β-strand	74-77	4	12
β-strand	78-80	3	13
α-helix	82-103	22
α-helix	106-108	3
α-helix	109-120	12
α-helix	121-123	3
β-strand	140-142	3	13
β-strand	145-147	3	12
β-strand	153-155	3	12
β-strand	157	1	14
β-strand	165	1	14
β-strand	169-172	4	11
α-helix	176-185	10
α-helix	193-207	15
α-helix	211-212	2
α-helix	214-216	3
β-strand	218-223	6	11
β-strand	227-230	4	11
α-helix	233-250	18

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

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Proteasome subunit alpha type-1	A	protein	252	Saccharomyces cerevisiae	P21243 (AlphaFold model)
Proteasome subunit alpha type-4	D	protein	254	Saccharomyces cerevisiae	P40303 (AlphaFold model)
Proteasome subunit alpha type-5	E	protein	260	Saccharomyces cerevisiae	P32379 (AlphaFold model)
Proteasome subunit alpha type-6	F	protein	234	Saccharomyces cerevisiae	P40302 (AlphaFold model)
Proteasome subunit beta type-1	H	protein	215	Saccharomyces cerevisiae	P38624
Proteasome maturation factor UMP1	3	protein	162	Saccharomyces cerevisiae	P38293
Proteasome chaperone 1	4	protein	276	Saccharomyces cerevisiae	Q05778
Proteasome assembly chaperone 2	5	protein	267	Saccharomyces cerevisiae	P36040
Proteasome subunit alpha type-2	B	protein	250	Saccharomyces cerevisiae	P23639
Proteasome subunit alpha type-3	C	protein	258	Saccharomyces cerevisiae	P23638
Probable proteasome subunit alpha type-7	G	protein	288	Saccharomyces cerevisiae	P21242
Proteasome subunit beta type-2	I	protein	261	Saccharomyces cerevisiae	P25043

2 more molecules are not listed.

Sequence of entity 1 (A), FASTA

>9RLA_1 Proteasome subunit alpha type-1 (chains A)
MSGAAAASAAGYDRHITIFSPEGRLYQVEYAFKATNQTNINSLAVRGKDCTVVISQKKVP
DKLLDPTTVSYIFCISRTIGMVVNGPIPDARNAALRAKAEAAEFRYKYGYDMPCDVLAKR
MANLSQIYTQRAYMRPLGVILTFVSVDEELGPSIYKTDPAGYYVGYKATATGPKQQEITT
NLENHFKKSKIDHINEESWEKVVEFAITHMIDALGTEFSKNDLEVGVATKDKFFTLSAEN
IEERLVAIAEQD

Sequence of entity 2 (D), FASTA

>9RLA_2 Proteasome subunit alpha type-4 (chains D)
MSGYDRALSIFSPDGHIFQVEYALEAVKRGTCAVGVKGKNCVVLGCERRSTLKLQDTRIT
PSKVSKIDSHVVLSFSGLNADSRILIEKARVEAQSHRLTLEDPVTVEYLTRYVAGVQQRY
TQSGGVRPFGVSTLIAGFDPRDDEPKLYQTEPSGIYSSWSAQTIGRNSKTVREFLEKNYD
RKEPPATVEECVKLTVRSLLEVVQTGAKNIEITVVKPDSDIVALSSEEINQYVTQIEQEK
QEQQEQDKKKKSNH

Sequence of entity 3 (E), FASTA

>9RLA_3 Proteasome subunit alpha type-5 (chains E)
MFLTRSEYDRGVSTFSPEGRLFQVEYSLEAIKLGSTAIGIATKEGVVLGVEKRATSPLLE
SDSIEKIVEIDRHIGCAMSGLTADARSMIEHARTAAVTHNLYYDEDINVESLTQSVCDLA
LRFGEGASGEERLMSRPFGVALLIAGHDADDGYQLFHAEPSGTFYRYNAKAIGSGSEGAQ
AELLNEWHSSLTLKEAELLVLKILKQVMEEKLDENNAQLSCITKQDGFKIYDNEKTAELI
KELKEKEAAESPEEADVEMS

Sequence of entity 4 (F), FASTA

>9RLA_4 Proteasome subunit alpha type-6 (chains F)
MFRNNYDGDTVTFSPTGRLFQVEYALEAIKQGSVTVGLRSNTHAVLVALKRNADELSSYQ
KKIIKCDEHMGLSLAGLAPDARVLSNYLRQQCNYSSLVFNRKLAVERAGHLLCDKAQKNT
QSYGGRPYGVGLLIIGYDKSGAHLLEFQPSGNVTELYGTAIGARSQGAKTYLERTLDTFI
KIDGNPDELIKAGVEAISQSLRDESLTVDNLSIAIVGKDTPFTIYDGEAVAKYI

Sequence of entity 5 (H), FASTA

>9RLA_5 Proteasome subunit beta type-1 (chains H)
MNGIQVDINRLKKGEVSLGTSIMAVTFKDGVILGADSRTTTGAYIANRVTDKLTRVHDKI
WCCRSGSAADTQAIADIVQYHLELYTSQYGTPSTETAASVFKELCYENKDNLTAGIIVAG
YDDKNKGEVYTIPLGGSVHKLPYAIAGSGSTFIYGYCDKNFRENMSKEETVDFIKHSLSQ
AIKWDGSSGGVIRMVVLTAAGVERLIFYPDEYEQL

Sequence of entity 6 (3), FASTA

>9RLA_6 Proteasome maturation factor UMP1 (chains 3)
DYKDDDDKHHHHHHMNIVPQDTFKSQVSTDQDKSVLSSAVPSLPDTLRQQEGGAVPPLST
QNDRHPLESTLKNWETTQRQRQMEQYRQIFGIAEPMKRTMEMEIVNRTDFNPLSTNGSIH
RDILLNKECSIDWEDVYPGTTGLQASMVGDDVHSKIEKQLGI

Sequence of entity 7 (4), FASTA

>9RLA_7 Proteasome chaperone 1 (chains 4)
MLFKQWNDLPEPKHLLDLPEISKNLQSLEVCPVPKVEFPQDLDVPQYSTAVITTKIMNPL
FPKNLLQLTSIGEIKTTLTVKSPSLPQSSGKHSWNYDENFPNEVDPDQKNDTADETVYGF
SFPIYSFGKTLLFSMEENFISISPIFGNMISRSIISQLAQFSPDIIVIGTSDKIASMKVM
TENECTLQPPEFITGFIGSVLTQLIVGPSKGLKFKCLVAPSEGPNGFEKLSLSDMGSLVD
LCGQWLGFEPSRYSEECYRLWRCDSAAIGAQSGLYI

Sequence of entity 8 (5), FASTA

>9RLA_8 Proteasome assembly chaperone 2 (chains 5)
MSCLVLPLVSVGNIPQLSIDWLLNSQANEWEYLEALDSKYLVEFVGPLDRPEDGSDSLYK
DADMKYSSALEVFYNKKRGLFAIQQRTPLVSVNYLNNFIVEIILPFLSKYNISEICIWDS
LYAMEDENGVIVRPQEVYSLGEFYFDDEAELLSNLHLNDQESMVNNWLHFTPTSFQDKIS
VDQPIFKILFQILNASQRPKALRSIKYCSCLANEGDNSLDSQQFLQWIISQKVIKNAPPI
VKFVRPISWQGAYGMADARDKFVDLYN

Sequence of entity 9 (B), FASTA

>9RLA_9 Proteasome subunit alpha type-2 (chains B)
MTDRYSFSLTTFSPSGKLGQIDYALTAVKQGVTSLGIKATNGVVIATEKKSSSPLAMSET
LSKVSLLTPDIGAVYSGMGPDYRVLVDKSRKVAHTSYKRIYGEYPPTKLLVSEVAKIMQE
ATQSGGVRPFGVSLLIAGHDEFNGFSLYQVDPSGSYFPWKATAIGKGSVAAKTFLEKRWN
DELELEDAIHIALLTLKESVEGEFNGDTIELAIIGDENPDLLGYTGIPTDKGPRFRKLTS
QEINDRLEAL

Sequence of entity 10 (C), FASTA

>9RLA_10 Proteasome subunit alpha type-3 (chains C)
MGSRRYDSRTTIFSPEGRLYQVEYALESISHAGTAIGIMASDGIVLAAERKVTSTLLEQD
TSTEKLYKLNDKIAVAVAGLTADAEILINTARIHAQNYLKTYNEDIPVEILVRRLSDIKQ
GYTQHGGLRPFGVSFIYAGYDDRYGYQLYTSNPSGNYTGWKAISVGANTSAAQTLLQMDY
KDDMKVDDAIELALKTLSKTTDSSALTYDRLEFATIRKGANDGEVYQKIFKPQEIKDILV
KTGITKKDEDEEADEDMK

Sequence of entity 11 (G), FASTA

>9RLA_11 Probable proteasome subunit alpha type-7 (chains G)
MTSIGTGYDLSNSVFSPDGRNFQVEYAVKAVENGTTSIGIKCNDGVVFAVEKLITSKLLV
PQKNVKIQVVDRHIGCVYSGLIPDGRHLVNRGREEAASFKKLYKTPIPIPAFADRLGQYV
QAHTLYNSVRPFGVSTIFGGVDKNGAHLYMLEPSGSYWGYKGAATGKGRQSAKAELEKLV
DHHPEGLSAREAVKQAAKIIYLAHEDNKEKDFELEISWCSLSETNGLHKFVKGDLLQEAI
DFAQKEINGDDDEDEDDSDNVMSSDDENAPVATNANATTDQEGDIHLE

Sequence of entity 12 (I), FASTA

>9RLA_12 Proteasome subunit beta type-2 (chains I)
MAGLSFDNYQRNNFLAENSHTQPKATSTGTTIVGVKFNNGVVIAADTRSSTQGPIVADKN
AKLHRISPKIWCAGAGTAADTEAVTQLIGSNIELHSLYTSREPRVVSALQMLKQHLFKYQ
GHIGAYLIVAGVDPTGSHLFSIHAHGSTDVGYYLSLGSGSLAAMAVLESHWKQDLTKEEA
IKLASDAIQAGIWNDLGSGSNVDVCVMEIGKDAEYLRNYLTTPNVREEKQKSYKFPRGTT
AVLKSIVNICDIQEEQVDITT

Primary citation

Structural transitions in the stepwise assembly of proteasome core particles. Mark, E., Ramos, P.C., Nunes, M.M. et al. Nat Commun (2026) 17. DOI 10.1038/s41467-026-70525-w · PubMed

Other PDB entries of the same protein (UniProt P21243 (AlphaFold model), which also has an AlphaFold model), best resolution first:

1RYP 1.9 Å, Crystal structure of the 20S proteasome from yeast at 2.4 Å resolution
8RVQ 2.02 Å, 20S proteasome from pre1-1
4R17 2.1 Å, Ligand-induced aziridine-formation at subunit beta5 of the yeast 20S proteasome
8RVL 2.14 Å, Proteasomal late precursor complex from pre1-1
8U7U 2.16 Å, Proteasome 20S Core Particle from Beta 3 D205 deletion
1G65 2.25 Å, Crystal structure of epoxomicin:20s proteasome reveals a molecular basis for selectivity…
8RVP 2.28 Å, Proteasomal late precursor complex from pre1-1, state 2
4QVP 2.3 Å, yCP beta5-M45T mutant in complex with bortezomib
5CZ4 2.3 Å, Yeast 20S proteasome at 2.3 A resolution
6HWE 2.3 Å, Yeast 20S proteasome beta2-G45A mutant in complex with carfilzomib
9GBK 2.39 Å, Blm10-20S proteasome complex from pre1-1
1G0U 2.4 Å, A gated channel into the proteasome core particle

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