25GE: Human KPTN-ITFG2-SZT2(2189-3432) complex

Cryo-EM structure of the human KPTN-ITFG2-SZT2(2189-3432) complex. Determined by electron microscopy at 3.37 Å resolution. Released 26 Aug 2026.

Method: Electron microscopy
Resolution: 3.37 Å
Organism: Homo sapiens
Chains: 3
Atoms: 13,064
Mol. weight: 235.52 kDa
Released: 26 Aug 2026

Explore 25GE in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

25GE contains 53 α-helices and 95 β-strands across 3 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: 8 helices, 34 β-strands

Element	Residues	Length	Sheet
β-strand	14-21	8	1
α-helix	22	1
β-strand	31-32	2	2
β-strand	41-44	4	2
β-strand	50-58	9	2
β-strand	61-66	6	2
β-strand	82-87	6	3
α-helix	88-89	2
β-strand	95-100	6	3
β-strand	102-103	2	4
β-strand	110-111	2	4
β-strand	112	1	5
β-strand	114-116	3	3
α-helix	127-130	4
β-strand	135	1	3
β-strand	138	1	5
β-strand	146	1	6
β-strand	149-153	5	7
β-strand	156-160	5	7
β-strand	161-164	4	6
β-strand	170-176	7	6
β-strand	181-185	5	6
α-helix	187-190	4
β-strand	201-208	8	8
α-helix	209	1
β-strand	214-221	8	8
β-strand	225-232	8	8
β-strand	237-245	9	8
β-strand	250-257	8	9
β-strand	273-279	7	9
β-strand	285-287	3	9
α-helix	290-293	4
β-strand	299-300	2	9
β-strand	310-316	7	10
β-strand	325-330	6	10
β-strand	334-341	8	10
α-helix	343-345	3
β-strand	353-361	9	10
β-strand	366-372	7	1
β-strand	381-386	6	1
β-strand	389-395	7	1
α-helix	397-421	25

Chain B: 5 helices, 29 β-strands

Element	Residues	Length	Sheet
β-strand	2-4	3	11
β-strand	9-13	5	12
β-strand	23-26	4	13
β-strand	35-39	5	13
β-strand	44-48	5	13
β-strand	57-60	4	13
β-strand	65-71	7	14
β-strand	80-85	6	14
β-strand	89-93	5	14
α-helix	97-98	2
α-helix	115-117	3
β-strand	119-122	4	14
β-strand	127-133	7	15
β-strand	142-147	6	15
β-strand	151-158	8	15
β-strand	170-178	9	15
β-strand	186-190	5	16
β-strand	196-202	7	16
β-strand	206-210	5	16
β-strand	240-244	5	16
β-strand	256-259	4	17
β-strand	275-280	6	17
β-strand	284-289	6	17
β-strand	296-302	7	17
β-strand	307-313	7	11
β-strand	322-327	6	11
β-strand	331-335	5	11
β-strand	341-345	5	11
β-strand	350-359	10	12
β-strand	365-373	9	12
β-strand	377-381	5	12
α-helix	394-399	6
α-helix	403-411	9
α-helix	418-429	12

Chain C: 40 helices, 32 β-strands

Element	Residues	Length	Sheet
α-helix	2202	1
β-strand	2203	1	18
α-helix	2204	1
α-helix	2205-2211	7
α-helix	2216-2218	3
β-strand	2220-2225	6	19
α-helix	2228-2230	3
α-helix	2234-2248	15
β-strand	2250	1	19
β-strand	2254	1	18
α-helix	2259-2261	3
α-helix	2263-2265	3
α-helix	2268-2269	2
α-helix	2275-2277	3
β-strand	2278-2283	6	19
β-strand	2293-2302	10	19
β-strand	2308	1	19
α-helix	2330-2333	4
β-strand	2337-2338	2	19
β-strand	2354-2363	10	19
α-helix	2367-2386	20
α-helix	2387-2391	5
β-strand	2397-2398	2	20
α-helix	2500-2511	12
β-strand	2517-2518	2	20
α-helix	2520-2522	3
α-helix	2525-2536	12
β-strand	2541-2547	7	21
α-helix	2551-2553	3
α-helix	2554-2568	15
β-strand	2573-2579	7	21
β-strand	2588-2591	4	21
α-helix	2593-2595	3
β-strand	2608-2613	6	21
α-helix	2615-2619	5
β-strand	2635	1	22
α-helix	2640-2642	3
β-strand	2644	1	22
β-strand	2649-2655	7	21
β-strand	2658-2664	7	21
α-helix	2668-2699	32
α-helix	2729-2734	6
α-helix	2738-2740	3
α-helix	2764-2766	3
α-helix	2789-2823	35
α-helix	2829-2831	3
β-strand	2832	1	23
α-helix	2834-2842	9
β-strand	2845-2853	9	24
α-helix	2858-2861	4
α-helix	2907-2927	21
β-strand	2930-2931	2	24
β-strand	2934	1	23
α-helix	2935-2938	4
β-strand	2981-2987	7	24
β-strand	2990-2999	10	24
β-strand	3002-3011	10	24
α-helix	3012-3014	3
α-helix	3020-3022	3
α-helix	3023-3038	16
α-helix	3042-3059	18
β-strand	3068	1	25
α-helix	3071-3081	11
β-strand	3092-3101	10	25
α-helix	3107-3116	10
α-helix	3118-3121	4
β-strand	3124-3129	6	25
β-strand	3137-3152	16	25
β-strand	3158-3171	14	25
α-helix	3183-3185	3
β-strand	3186-3197	12	25
α-helix	3249-3283	35

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
KICSTOR complex protein kaptin	A	protein	437	Homo sapiens	Q9Y664 (AlphaFold model)
KICSTOR complex protein ITFG2	B	protein	447	Homo sapiens	Q969R8 (AlphaFold model)
KICSTOR complex protein SZT2	C	protein	1245	Homo sapiens	Q5T011 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>25GE_1 KICSTOR complex protein kaptin (chains A)
GMMGEAAVAAGPCPLREDSFTRFSSQSNVYGLAGGAGGRGELLAATLKGKVLGFRYQDLR
QKIRPVAKELQFNYIPVDAEIVSIDTFNKSPPKRGLVVGITFIKDSGDKGSPFLNIYCDY
EPGSEYNLDSIAQSCLNLELQFTPFQLCHAEVQVGDQLETVFLLSGNDPAIHLYKENEGL
HQFEEQPVENLFPELTNLTSSVLWLDVHNFPGTSRRLSALGCQSGYVRVAHVDQRSREVL
QMWSVLQDGPISRVIVFSLSAAKETKDRPLQDEYSVLVASMLEPAVVYRDLLNRGLEDQL
LLPGSDQFDSVLCSLVTDVDLDGRPEVLVATYGQELLCYKYRGPESGLPEAQHGFHLLWQ
RSFSSPLLAMAHVDLTGDGLQELAVVSLKGVHILQHSLIQASELVLTRLRHQVEQRRRRL
QGLEDGAGAGPAENAAS

Sequence of entity 2 (B), FASTA

>25GE_2 KICSTOR complex protein ITFG2 (chains B)
MRSVSYVQRVALEFSGSLFPHAICLGDVDNDTLNELVVGDTSGKVSVYKNDDSRPWLTCS
CQGMLTCVGVGDVCNKGKNLLVAVSAEGWFHLFDLTPAKVLDASGHHETLIGEEQRPVFK
QHIPANTKVMLISDIDGDGCRELVVGYTDRVVRAFRWEELGEGPEHLTGQLVSLKKWMLE
GQVDSLSVTLGPLGLPELMVSQPGCAYAILLCTWKKDTGSPPASEGPTDGSRETPAARDV
VLHQTSGRIHNKNVSTHLIGNIKQGHGTESSGSGLFALCTLDGTLKLMEEMEEADKLLWS
VQVDHQLFALEKLDVTGNGHEEVVACAWDGQTYIIDHNRTVVRFQVDENIRAFCAGLYAC
KEGRNSPCLVYVTFNQKIYVYWEVQLERMESTNLVKLLETKPEYHSLLQELGVDPDDLPV
TRALLHQTLYHPDQPPQCAPSSLQDPT

Sequence of entity 3 (C), FASTA

>25GE_3 KICSTOR complex protein SZT2 (chains C)
GTLDVITVMLVRNCKLTPADVEFIQPPGSLPSEVLHLALPTSCRPWLPALAWYLRQNLLI
FLHSPKYTDSNSRNHFQHPLPPQGGLPDLDIYLYNKPGGQGTGGKGVACITLAFVDEGGA
PLSLALWPPSSPGPPDPLREEEFEQLTQVIRCPVVVDSSSAQNGAPRLRLDVWEKGNISI
VQLEEKLRGAARQALADAIIELQLLPASLCTEDTPTGSLRNGSLETKSSAGRASTFPPAP
VPGEPVTPPSKAGRRSFWDMLSKTECGDLGSPKTTDDIVLDRPEDTRGRRRHKTESVRTP
GGAERAPGSDSGAQRQKRRTTQLEEGEVGTLHPVFARVAQRWMEFMVQIGCASVSRSSAH
MVSRFLLPSILSEFTALVTSMAGDTSVRIFEQHLGSEPEIFGPCSPGQLGPSPRPAAERH
LLLLGRNFLQWRRPTQQAAKAMQRFEPGGDGSSGRNAPRQRLLLLEVVDKKLQLLTYNWA
PDLGAALGRALVRLVQWQNARAHLIFCLLSQKLGLFHHYGQLDFPVRDEKEPNPFLLPTM
EVETLIRSASPPLSREQGRLSGSSRGGGPLPLDTFPFDEALRDITAARPSSVLGPVPRPP
DPVTYHGQQFLEIKMAERRELERQMKMENLFVTWQQRSTPATMPISAGELETLKQSSRLV
HYCATAMLFDPAAWLHGPPETSGPPDGQRRHRPESGSGSREAPTSCESLDVSPPGAREEP
WLKELSLAFLQQYVQYLQSIGFVLVPLRPPSPARSTSRPRAMAILGTEGRGSFSCPKTKT
DGSPKSTSSPVTTYHLQRALPGGIILMELAFQGCYFCVKQFALECSRIPMGQAVNSQLSM
LFTEECDKVRDLMHVHSFSYDFHLRLVHQHVLGAHLVLRHGYHLTTFLRHFLAHHPDGPH
FGRNHIYQGTLELPTPLIAAHQLYNYVADHASSYHMKPLRMARPGGPEHNEYALVSAWHS
SGSYLDSEGLRHQDDFDVSLLVCHCAAPFEEQGEAERHVLRLQFFVVLTSQRELFPRLTA
DMRRFRKPPRLPPEPEAPGSSAGSPGEASGLILAPGPAPLFPPLAAEVGMARARLAQLVR
LAGGHCRRDTLWKRLFLLEPPGPDRLRLGGRLALAELEELLEAVHAKSIGDIDPQLDCFL
SMTVSWYQSLIKVLLSRFPQSCRHFQSPDLGTQYLVVLNQKFTDCFVLVFLDSHLGKTSL
TVVFREPFPVQPQDSESPPAQLVSTYHHLESVINTACFTLWTRLL

Primary citation

Mechanistic insights into GATOR1 inhibition by GATOR2 and KICSTOR. Yang, A., Liang, L. To be published.

Other PDB entries of the same protein (UniProt Q9Y664 (AlphaFold model), which also has an AlphaFold model), best resolution first:

9VAN 2.9 Å, Cryo-EM structure of human full length KICSTOR complex (state 2)
9V80 2.95 Å, Cryo-EM structure of KICSTOR CCC complex (state 4)
9V86 3.04 Å, Cryo-EM structure of KICSTOR CCC complex (state 3)
9V9N 3.08 Å, Cryo-EM structure of KICSTOR CCC complex (state 5)
9V6E 3.19 Å, Cryo-EM structure of human full length KICSTOR complex (state 1)
9O5A 3.2 Å, The KICSTOR-GATOR1 complex
25GF 3.81 Å, Cryo-EM structure of the human KPTN-ITFG2-C12orf66-SZT2(2189-3432) complex

Browse structure collections

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