1SQB: PDB entry 1SQB

Crystal Structure Analysis of Bovine Bc1 with Azoxystrobin. Determined by X-ray diffraction at 2.69 Å resolution. Released 7 Sept 2004.

Method: X-ray diffraction
Resolution: 2.69 Å
Organism: Bos taurus
Chains: 11
Atoms: 16,897
Mol. weight: 248.83 kDa
Ligands: FES, HEC, AZO, HEM
Released: 7 Sept 2004

Explore 1SQB in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

1SQB contains 118 α-helices and 58 β-strands across 11 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: 27 helices, 14 β-strands

Element	Residues	Length	Sheet
α-helix	4-10	7
α-helix	12-13	2
β-strand	15-18	4	1
β-strand	24-29	6	1
β-strand	34-41	8	1
α-helix	50-52	3
α-helix	55-62	8
β-strand	67	1	2
α-helix	74-81	8
β-strand	85-90	6	1
β-strand	95-102	8	1
α-helix	103-105	3
α-helix	106-118	13
β-strand	120	1	2
α-helix	124-142	19
α-helix	145-157	13
α-helix	162-164	3
α-helix	171-176	6
α-helix	179-189	11
α-helix	192-194	3
β-strand	195-201	7	1
α-helix	205-215	11
α-helix	230-233	4
β-strand	239-245	7	3
β-strand	251-259	9	3
α-helix	267-277	11
β-strand	279-281	3	3
α-helix	287-289	3
α-helix	293-300	8
β-strand	306-314	9	3
β-strand	317-326	10	3
α-helix	328-330	3
α-helix	331-348	18
α-helix	351-368	18
α-helix	372-385	14
α-helix	392-400	9
α-helix	404-414	11
α-helix	419-420	2
β-strand	421-426	6	3
α-helix	432-433	2
α-helix	434-439	6

Chain B: 24 helices, 16 β-strands

Element	Residues	Length	Sheet
α-helix	17-24	8
β-strand	25-28	4	4
β-strand	34-38	5	4
β-strand	44-51	8	4
α-helix	55-57	3
α-helix	65-71	7
β-strand	77	1	5
α-helix	82-91	10
β-strand	95-100	6	4
β-strand	105-112	8	4
α-helix	113-115	3
α-helix	116-128	13
β-strand	130	1	5
α-helix	134-140	7
α-helix	142-151	10
α-helix	155-167	13
β-strand	168	1	6
α-helix	180-182	3
α-helix	188-198	11
α-helix	201-203	3
β-strand	204-209	6	4
α-helix	213-223	11
β-strand	239	1	6
β-strand	242-247	6	7
β-strand	252-260	9	7
α-helix	267-279	13
β-strand	285	1	1
α-helix	294-302	9
β-strand	307-315	9	7
β-strand	320-329	10	7
α-helix	333-348	16
α-helix	354-371	18
α-helix	375-389	15
α-helix	395-404	10
α-helix	407-419	13
α-helix	421	1
β-strand	422-428	7	7
α-helix	430-432	3
α-helix	433-435	3
α-helix	436-438	3

Chain C: 24 helices, 5 β-strands

Element	Residues	Length	Sheet
α-helix	4-7	4
α-helix	9-14	6
α-helix	15-19	5
β-strand	22-24	3	8
α-helix	29-31	3
α-helix	33-52	20
α-helix	62-71	10
α-helix	76-103	28
α-helix	106-108	3
α-helix	110-132	23
β-strand	136	1	9
α-helix	137-147	11
α-helix	148-152	5
α-helix	157-165	9
α-helix	172-201	30
α-helix	214-216	3
β-strand	217-219	3	8
α-helix	220-245	26
α-helix	253-256	4
β-strand	258	1	9
α-helix	272-283	12
α-helix	287-299	13
α-helix	300-302	3
α-helix	304-307	4
β-strand	312	1	10
α-helix	319-339	21
α-helix	345-360	16
α-helix	361-365	5
α-helix	366-376	11

Chain D: 13 helices, 9 β-strands

Element	Residues	Length	Sheet
α-helix	6-8	3
α-helix	23-32	10
α-helix	33-37	5
β-strand	47	1	11
α-helix	49-51	3
β-strand	52	1	12
β-strand	56	1	12
α-helix	58-65	8
β-strand	69-74	6	13
β-strand	80-84	5	13
α-helix	85-86	2
β-strand	90	1	11
α-helix	91-93	3
α-helix	100-103	4
α-helix	109-112	4
α-helix	124-132	9
α-helix	136-138	3
β-strand	148-149	2	14
β-strand	157-158	2	14
α-helix	179-192	14
α-helix	198-231	34
β-strand	234-237	4	3

Chain E: 7 helices, 9 β-strands

Element	Residues	Length	Sheet
α-helix	6-9	4
β-strand	14	1	15
α-helix	16-18	3
α-helix	26-63	38
α-helix	66-69	4
β-strand	75-77	3	16
β-strand	89-90	2	17
β-strand	95-100	6	17
α-helix	101-102	2
α-helix	106-109	4
β-strand	132-136	5	17
β-strand	147	1	18
β-strand	156-157	2	18
β-strand	164-165	2	18
α-helix	179-181	3
β-strand	192-194	3	16

Chain F: 9 helices, 1 β-strand

Element	Residues	Length	Sheet
α-helix	10-24	15
α-helix	27-29	3
α-helix	33-35	3
β-strand	37	1	10
α-helix	41-48	8
α-helix	52-71	20
α-helix	77-79	3
α-helix	81-82	2
α-helix	83-85	3
α-helix	91-107	17

Chain G: 2 helices, 2 β-strands

Element	Residues	Length	Sheet
β-strand	11-18	8	3
β-strand	23	1	15
α-helix	33-42	10
α-helix	45-67	23

Chain H: 3 helices, 0 β-strands

Element	Residues	Length
α-helix	16-24	9
α-helix	28-46	19
α-helix	55-72	18

3 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
Ubiquinol-cytochrome C reductase complex core protein I, mitochondrial	A	protein	480	Bos taurus	P31800 (AlphaFold model)
Ubiquinol-cytochrome C reductase complex core protein 2, mitochondrial	B	protein	453	Bos taurus	P23004 (AlphaFold model)
Cytochrome b	C	protein	379	Bos taurus	P00157 (AlphaFold model)
Cytochrome c1, heme protein, mitochondrial	D	protein	241	Bos taurus	P00125 (AlphaFold model)
Ubiquinol-cytochrome c reductase iron-sulfur subunit	E	protein	196	Bos taurus	P13272
Ubiquinol-cytochrome C reductase complex 14 kDa protein	F	protein	110	Bos taurus	P00129
Ubiquinol-cytochrome C reductase complex ubiquinone-binding protein QP-C	G	protein	81	Bos taurus	P13271
Ubiquinol-cytochrome C reductase complex 11 kDa protein	H	protein	78	Bos taurus	P00126
Ubiquinol-cytochrome c reductase 8 kDa protein	I	protein	78	Bos taurus	P13272
Ubiquinol-cytochrome C reductase complex 7.2 kDa protein	J	protein	62	Bos taurus	P00130
Ubiquinol-cytochrome C reductase complex 6.4 kDa protein	K	protein	56	Bos taurus	P07552

Sequence of entity 1 (A), FASTA

>1SQB_1 Ubiquinol-cytochrome C reductase complex core protein I, mitochondrial (chains A)
MAASAVCRAAGAGTRVLLRTRRSPALLRSSDLRGTATYAQALQSVPETQVSQLDNGLRVA
SEQSSQPTCTVGVWIDAGSRYESEKNNGAGYFVEHLAFKGTKNRPGNALEKEVESMGAHL
NAYSTREHTAYYIKALSKDLPKAVELLADIVQNCSLEDSQIEKERDVILQELQENDTSMR
DVVFNYLHATAFQGTPLAQSVEGPSENVRKLSRADLTEYLSRHYKAPRMVLAAAGGLEHR
QLLDLAQKHFSGLSGTYDEDAVPTLSPCRFTGSQICHREDGLPLAHVAIAVEGPGWAHPD
NVALQVANAIIGHYDCTYGGGAHLSSPLASIAATNKLCQSFQTFNICYADTGLLGAHFVC
DHMSIDDMMFVLQGQWMRLCTSATESEVLRGKNLLRNALVSHLDGTTPVCEDIGRSLLTY
GRRIPLAEWESRIAEVDARVVREVCSKYFYDQCPAVAGFGPIEQLPDYNRIRSGMFWLRF

Sequence of entity 2 (B), FASTA

>1SQB_2 Ubiquinol-cytochrome C reductase complex core protein 2, mitochondrial (chains B)
MKLLTRAGSLSRFYSLKVAPKVKATEAPAGVPPHPQDLEFTRLPNGLVIASLENYAPASR
IGLFIKAGSRYENSNNLGTSHLLRLASSLTTKGASSFKITRGIEAVGGKLSVTSTRENMA
YTVECLRDDVDILMEFLLNVTTAPEFRRWEVAALQPQLRIDKAVALQNPQAHVIENLHAA
AYRNALANSLYCPDYRIGKVTPVELHDYVQNHFTSARMALIGLGVSHPVLKQVAEQFLNI
RGGLGLSGAKAKYHGGEIREQNGDSLVHAALVAESAAIGSAEANAFSVLQHVLGAGPHVK
RGSNATSSLYQAVAKGVHQPFDVSAFNASYSDSGLFGFYTISQAASAGDVIKAAYNQVKT
IAQGNLSNPDVQAAKNKLKAGYLMSVESSEGFLDEVGSQALAAGSYTPPSTVLQQIDAVA
DADVINAAKKFVSGRKSMAASGNLGHTPFIDEL

Sequence of entity 3 (C), FASTA

>1SQB_3 Cytochrome b (chains C)
MTNIRKSHPLMKIVNNAFIDLPAPSNISSWWNFGSLLGICLILQILTGLFLAMHYTSDTT
TAFSSVTHICRDVNYGWIIRYMHANGASMFFICLYMHVGRGLYYGSYTFLETWNIGVILL
LTVMATAFMGYVLPWGQMSFWGATVITNLLSAIPYIGTNLVEWIWGGFSVDKATLTRFFA
FHFILPFIIMAIAMVHLLFLHETGSNNPTGISSDVDKIPFHPYYTIKDILGALLLILALM
LLVLFAPDLLGDPDNYTPANPLNTPPHIKPEWYFLFAYAILRSIPNKLGGVLALAFSILI
LALIPLLHTSKQRSMMFRPLSQCLFWALVADLLTLTWIGGQPVEHPYITIGQLASVLYFL
LILVLMPTAGTIENKLLKW

Sequence of entity 4 (D), FASTA

>1SQB_4 Cytochrome c1, heme protein, mitochondrial (chains D)
SDLELHPPSYPWSHRGLLSSLDHTSIRRGFQVYKQVCSSCHSMDYVAYRHLVGVCYTEDE
AKALAEEVEVQDGPNEDGEMFMRPGKLSDYFPKPYPNPEAARAANNGALPPDLSYIVRAR
HGGEDYVFSLLTGYCEPPTGVSLREGLYFNPYFPGQAIGMAPPIYNEVLEFDDGTPATMS
QVAKDVCTFLRWAAEPEHDHRKRMGLKMLLMMGLLLPLVYAMKRHKWSVLKSRKLAYRPP
K

Sequence of entity 5 (E), FASTA

>1SQB_5 Ubiquinol-cytochrome c reductase iron-sulfur subunit (chains E)
SHTDIKVPDFSDYRRPEVLDSTKSSKESSEARKGFSYLVTATTTVGVAYAAKNVVSQFVS
SMSASADVLAMSKIEIKLSDIPEGKNMAFKWRGKPLFVRHRTKKEIDQEAAVEVSQLRDP
QHDLERVKKPEWVILIGVCTHLGCVPIANAGDFGGYYCPCHGSHYDASGRIRKGPAPLNL
EVPSYEFTSDDMVIVG

Sequence of entity 6 (F), FASTA

>1SQB_6 Ubiquinol-cytochrome C reductase complex 14 kDa protein (chains F)
AGRPAVSASSRWLEGIRKWYYNAAGFNKLGLMRDDTIHENDDVKEAIRRLPENLYDDRVF
RIKRALDLSMRQQILPKEQWTKYEEDKSYLEPYLKEVIRERKEREEWAKK

Sequence of entity 7 (G), FASTA

>1SQB_7 Ubiquinol-cytochrome C reductase complex ubiquinone-binding protein QP-C (chains G)
GRQFGHLTRVRHVITYSLSPFEQRAFPHYFSKGIPNVLRRTRACILRVAPPFVAFYLVYT
WGTQEFEKSKRKNPAAYENDR

Sequence of entity 8 (H), FASTA

>1SQB_8 Ubiquinol-cytochrome C reductase complex 11 kDa protein (chains H)
GDPKEEEEEEEELVDPLTTVREQCEQLEKCVKARERLELCDERVSSRSQTEEDCTEELLD
FLHARDHCVAHKLFNSLK

Sequence of entity 9 (I), FASTA

>1SQB_9 Ubiquinol-cytochrome c reductase 8 kDa protein (chains I)
MLSVAARSGPFAPVLSATSRGVAGALRPLVQAAVPATSESPVLDLKRSVLCRESLRGQAA
GRPLVASVSLNVPASVRY

Sequence of entity 10 (J), FASTA

>1SQB_10 Ubiquinol-cytochrome C reductase complex 7.2 kDa protein (chains J)
VAPTLTARLYSLLFRRTSTFALTIVVGALFFERAFDQGADAIYEHINEGKLWKHIKHKYE
NK

Sequence of entity 11 (K), FASTA

>1SQB_11 Ubiquinol-cytochrome C reductase complex 6.4 kDa protein (chains K)
MLTRFLGPRYRQLARNWVPTAQLWGAVGAVGLVWATDSRLILDWVPYINGKFKKDD

Ligands and cofactors

ID	Name	Formula	Copies
FES	FE2/S2 (inorganic) cluster	Fe2 S2	1
HEC	Heme C	C34 H36 Fe N4 O4	1
AZO	Methyl (2Z)-2-(2-{[6-(2-cyanophenoxy)pyrimidin-4-yl]oxy}phenyl)-3-methoxyacryla…	C22 H17 N3 O5	1
HEM	Protoporphyrin IX containing FE	C34 H32 Fe N4 O4	2

Primary citation

Crystallographic studies of quinol oxidation site inhibitors: a modified classification of inhibitors for the cytochrome bc(1) complex. Esser, L., Quinn, B., Li, Y.F. et al. J Mol Biol (2004) 341:281-302. DOI 10.1016/j.jmb.2004.05.065 · PubMed

Other PDB entries of the same protein (UniProt P31800 (AlphaFold model), which also has an AlphaFold model), best resolution first:

1PP9 2.1 Å, Bovine cytochrome bc1 complex with stigmatellin bound
1PPJ 2.1 Å, Bovine cytochrome bc1 complex with stigmatellin and antimycin
2A06 2.1 Å, Bovine cytochrome bc1 complex with stigmatellin bound
9W2X 2.2 Å, Cryo-EM structure of complex III on the bovine heart submitochondrial particles, III-1
2FYU 2.26 Å, Crystal structure of bovine heart mitochondrial bc1 with jg144 inhibitor
1L0L 2.35 Å, structure of bovine mitochondrial cytochrome bc1 complex with a bound fungicide famoxadone
1NTM 2.4 Å, Crystal Structure of Mitochondrial Cytochrome bc1 Complex at 2.4 Angstrom
9W2Y 2.4 Å, Cryo-EM structure of complex III on the bovine heart submitochondrial particles, III-2
1L0N 2.6 Å, native structure of bovine mitochondrial cytochrome bc1 complex
1NTK 2.6 Å, Crystal Structure of Mitochondrial Cytochrome bc1 in Complex with Antimycin A1
1NTZ 2.6 Å, Crystal Structure of Mitochondrial Cytochrome bc1 Complex Bound with Ubiquinone
1SQX 2.6 Å, Crystal Structure Analysis of Bovine Bc1 with Stigmatellin A

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