UniProtKB - O75908 (SOAT2_HUMAN)
Sterol O-acyltransferase 2
SOAT2
Functioni
Catalyzes the formation of fatty acid-cholesterol esters, which are less soluble in membranes than cholesterol (PubMed:16647063, PubMed:11294643).
Plays a role in lipoprotein assembly and dietary cholesterol absorption (PubMed:11294643).
Utilizes oleoyl-CoA ((9Z)-octadecenoyl-CoA) and linolenoyl-CoA ((9Z,12Z,15Z)-octadecatrienoyl-CoA) as substrates (PubMed:11294643).
May provide cholesteryl esters for lipoprotein secretion from hepatocytes and intestinal mucosa (PubMed:11294643).
2 PublicationsHas lower enzymatic activity compared to isoform 1.
1 PublicationHas lower enzymatic activity compared to isoform 1.
1 PublicationCatalytic activityi
- EC:2.3.1.261 Publication1 Publication
- This reaction proceeds in the forward1 Publication direction.
- (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoyl-CoA + cholesterol = (5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl)-cholesterol + CoA1 PublicationThis reaction proceeds in the forward1 Publication direction.
- (9Z,12Z,15Z)-octadecatrienoyl-CoA + cholesterol = (9Z,12Z,15Z-octadecatrienoyl)-cholesterol + CoA1 PublicationThis reaction proceeds in the forward1 Publication direction.
- (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + cholesterol = cholesteryl (5Z,8Z,11Z,14Z)-eicosatetraenoate + CoA1 PublicationThis reaction proceeds in the forward1 Publication direction.
Sites
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Binding sitei | 119 | CholesterolBy similarity | 1 | |
Binding sitei | 389 | Acyl-CoABy similarity | 1 | |
Binding sitei | 392 | Acyl-CoABy similarity | 1 | |
Binding sitei | 395 | Acyl-CoABy similarity | 1 | |
Binding sitei | 399 | Acyl-CoABy similarity | 1 | |
Binding sitei | 407 | Acyl-CoABy similarity | 1 | |
Binding sitei | 430 | Acyl-CoABy similarity | 1 | |
Active sitei | 434 | 1 Publication | 1 |
GO - Molecular functioni
- acyltransferase activity Source: ProtInc
- cholesterol binding Source: BHF-UCL
- cholesterol O-acyltransferase activity Source: BHF-UCL
- fatty-acyl-CoA binding Source: BHF-UCL
- O-acyltransferase activity Source: GO_Central
- sterol O-acyltransferase activity Source: UniProtKB
GO - Biological processi
- cholesterol efflux Source: BHF-UCL
- cholesterol esterification Source: UniProtKB
- cholesterol homeostasis Source: BHF-UCL
- cholesterol metabolic process Source: UniProtKB
- intestinal cholesterol absorption Source: BHF-UCL
- low-density lipoprotein particle clearance Source: Reactome
- macrophage derived foam cell differentiation Source: BHF-UCL
- very-low-density lipoprotein particle assembly Source: BHF-UCL
Keywordsi
Molecular function | Acyltransferase, Transferase |
Biological process | Cholesterol metabolism, Lipid metabolism, Steroid metabolism, Sterol metabolism |
Enzyme and pathway databases
BRENDAi | 2.3.1.26, 2681 |
PathwayCommonsi | O75908 |
Reactomei | R-HSA-8964038, LDL clearance |
SABIO-RKi | O75908 |
SignaLinki | O75908 |
Protein family/group databases
TCDBi | 2.A.50.4.11, the glycerol uptake (gup) or membrane-bound acyl transferase (mboat) family |
Chemistry databases
SwissLipidsi | SLP:000001262 [O75908-1] |
Names & Taxonomyi
Protein namesi | Recommended name: Sterol O-acyltransferase 2Curated (EC:2.3.1.261 Publication1 Publication)Alternative name(s): Acyl-coenzyme A:cholesterol acyltransferase 2 Short name: ACAT-2 Cholesterol acyltransferase 2 |
Gene namesi | |
Organismi | Homo sapiens (Human) |
Taxonomic identifieri | 9606 [NCBI] |
Taxonomic lineagei | Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo |
Proteomesi |
|
Organism-specific databases
HGNCi | HGNC:11178, SOAT2 |
MIMi | 601311, gene |
neXtProti | NX_O75908 |
VEuPathDBi | HostDB:ENSG00000167780 |
Subcellular locationi
Endoplasmic reticulum
- Endoplasmic reticulum membrane By similarity; Multi-pass membrane protein Sequence analysis
Endoplasmic reticulum
- endoplasmic reticulum Source: BHF-UCL
- endoplasmic reticulum membrane Source: BHF-UCL
Other locations
- brush border Source: BHF-UCL
- integral component of membrane Source: UniProtKB-KW
Topology
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Topological domaini | 1 – 120 | CytoplasmicCuratedAdd BLAST | 120 | |
Transmembranei | 121 – 142 | Helical; Name=1By similarityAdd BLAST | 22 | |
Topological domaini | 143 – 162 | LumenalCuratedAdd BLAST | 20 | |
Transmembranei | 163 – 188 | Helical; Name=2By similarityAdd BLAST | 26 | |
Topological domaini | 189 – 196 | CytoplasmicCurated | 8 | |
Transmembranei | 197 – 220 | Helical; Name=3By similarityAdd BLAST | 24 | |
Topological domaini | 221 – 228 | LumenalCurated | 8 | |
Transmembranei | 229 – 252 | Helical; Name=4By similarityAdd BLAST | 24 | |
Topological domaini | 253 – 293 | CytoplasmicCuratedAdd BLAST | 41 | |
Transmembranei | 294 – 326 | Helical; Name=5By similarityAdd BLAST | 33 | |
Topological domaini | 327 – 343 | LumenalCuratedAdd BLAST | 17 | |
Transmembranei | 344 – 369 | Helical; Name=6By similarityAdd BLAST | 26 | |
Topological domaini | 370 – 417 | CytoplasmicCuratedAdd BLAST | 48 | |
Transmembranei | 418 – 442 | Helical; Name=7By similarityAdd BLAST | 25 | |
Topological domaini | 443 – 448 | LumenalCurated | 6 | |
Transmembranei | 449 – 464 | Helical; Name=8By similarityAdd BLAST | 16 | |
Topological domaini | 465 – 470 | CytoplasmicCurated | 6 | |
Transmembranei | 471 – 502 | Helical; Name=9By similarityAdd BLAST | 32 | |
Topological domaini | 503 – 522 | LumenalCuratedAdd BLAST | 20 |
Keywords - Cellular componenti
Endoplasmic reticulum, MembranePathology & Biotechi
Mutagenesis
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Mutagenesisi | 49 | K → R in K-null mutant; does not affect ubiquitination and sterol-regulated stabilization; when associated with R-80, R-100, R-102, R-108, R-242 and R-299. 1 Publication | 1 | |
Mutagenesisi | 80 | K → R in K-null mutant; does not affect ubiquitination and sterol-regulated stabilization; when associated with R-49, R-100, R-102, R-108, R-242 and R-299. 1 Publication | 1 | |
Mutagenesisi | 100 | K → R in K-null mutant; does not affect ubiquitination and sterol-regulated stabilization; when associated with R-49, R-80, R-102, R-108, R-242 and R-299. 1 Publication | 1 | |
Mutagenesisi | 102 | K → R in K-null mutant; does not affect ubiquitination and sterol-regulated stabilization; when associated with R-49, R-80, R-100, R-108, R-242 and R-299. 1 Publication | 1 | |
Mutagenesisi | 108 | K → R in K-null mutant; does not affect ubiquitination and sterol-regulated stabilization; when associated with R-49, R-80, R-100, R-102, R-242 and R-299. 1 Publication | 1 | |
Mutagenesisi | 242 | K → R in K-null mutant; does not affect ubiquitination and sterol-regulated stabilization; when associated with R-49, R-80, R-100, R-102, R-108 and R-299. 1 Publication | 1 | |
Mutagenesisi | 254 | T → A: Does not affect ubiquitination and sterol-regulated stabilization; when associated with R-279. 1 Publication | 1 | |
Mutagenesisi | 267 – 270 | SFSS → AFAA: Does not affect ubiquitination and sterol-regulated stabilization. 1 Publication | 4 | |
Mutagenesisi | 277 | C → A: Abolished ubiquitination and sterol-regulated stabilization. 1 Publication | 1 | |
Mutagenesisi | 279 | T → A: Does not affect ubiquitination and sterol-regulated stabilization; when associated with R-54. 1 Publication | 1 | |
Mutagenesisi | 299 | K → R in K-null mutant; does not affect ubiquitination and sterol-regulated stabilization; when associated with R-49, R-80, R-100, R-102, R-108 and R-242. 1 Publication | 1 | |
Mutagenesisi | 360 | H → A: Abolished cholesterol O-acyltransferase activity. 1 Publication | 1 | |
Mutagenesisi | 399 | H → A: Abolished cholesterol O-acyltransferase activity. 1 Publication | 1 |
Organism-specific databases
DisGeNETi | 8435 |
OpenTargetsi | ENSG00000167780 |
PharmGKBi | PA36016 |
Miscellaneous databases
Pharosi | O75908, Tchem |
Chemistry databases
ChEMBLi | CHEMBL4465 |
DrugBanki | DB01094, Hesperetin |
Genetic variation databases
BioMutai | SOAT2 |
PTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
ChainiPRO_0000207645 | 1 – 522 | Sterol O-acyltransferase 2Add BLAST | 522 |
Amino acid modifications
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Modified residuei | 277 | Cysteine sulfenic acid (-SOH); alternate1 Publication | 1 | |
Cross-linki | 277 | Glycyl cysteine thioester (Cys-Gly) (interchain with G-Cter in ubiquitin); alternate1 Publication |
Post-translational modificationi
Keywords - PTMi
Oxidation, Thioester bond, Ubl conjugationProteomic databases
MassIVEi | O75908 |
PaxDbi | O75908 |
PeptideAtlasi | O75908 |
PRIDEi | O75908 |
ProteomicsDBi | 27608 50258 [O75908-1] |
PTM databases
iPTMneti | O75908 |
PhosphoSitePlusi | O75908 |
SwissPalmi | O75908 |
Expressioni
Tissue specificityi
Gene expression databases
Bgeei | ENSG00000167780, Expressed in liver and 87 other tissues |
ExpressionAtlasi | O75908, baseline and differential |
Genevisiblei | O75908, HS |
Organism-specific databases
HPAi | ENSG00000167780, Tissue enriched (intestine) |
Interactioni
Subunit structurei
May form homo- or heterodimers (By similarity).
Interacts with INSIG1; the interaction is direct and promotes association with AMFR/gp78 (PubMed:28604676).
By similarity1 PublicationBinary interactionsi
O75908
With | #Exp. | IntAct |
---|---|---|
TMBIM6 [P55061] | 3 | EBI-9055438,EBI-1045825 |
Protein-protein interaction databases
BioGRIDi | 114015, 5 interactors |
IntActi | O75908, 3 interactors |
MINTi | O75908 |
STRINGi | 9606.ENSP00000301466 |
Chemistry databases
BindingDBi | O75908 |
Miscellaneous databases
RNActi | O75908, protein |
Family & Domainsi
Region
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Regioni | 1 – 36 | DisorderedSequence analysisAdd BLAST | 36 | |
Regioni | 74 – 96 | DisorderedSequence analysisAdd BLAST | 23 |
Motif
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Motifi | 377 – 383 | FYXDWWN motifBy similarity | 7 |
Compositional bias
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Compositional biasi | 13 – 28 | Basic and acidic residuesSequence analysisAdd BLAST | 16 |
Domaini
Sequence similaritiesi
Keywords - Domaini
Transmembrane, Transmembrane helixPhylogenomic databases
eggNOGi | KOG0380, Eukaryota |
GeneTreei | ENSGT00950000183081 |
HOGENOMi | CLU_031845_1_0_1 |
InParanoidi | O75908 |
OMAi | MHDRHTG |
OrthoDBi | 1275897at2759 |
PhylomeDBi | O75908 |
TreeFami | TF315226 |
Family and domain databases
InterProi | View protein in InterPro IPR004299, MBOAT_fam IPR014371, Oat_ACAT_DAG_ARE IPR030687, Sterol_acyltranf_meta |
PANTHERi | PTHR10408, PTHR10408, 1 hit |
Pfami | View protein in Pfam PF03062, MBOAT, 1 hit |
PIRSFi | PIRSF000439, Oat_ACAT_DAG_ARE, 1 hit PIRSF500230, Sterol_acyltranf_ACAT, 1 hit |
s (4+)i Sequence
Sequence statusi: Complete.
This entry describes 4 produced by isoformsialternative splicing. AlignAdd to basketThis entry has 4 described isoforms and 1 potential isoform that is computationally mapped.Show allAlign All
This isoform has been chosen as the sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry. canonicali
10 20 30 40 50
MEPGGARLRL QRTEGLGGER ERQPCGDGNT ETHRAPDLVQ WTRHMEAVKA
60 70 80 90 100
QLLEQAQGQL RELLDRAMRE AIQSYPSQDK PLPPPPPGSL SRTQEPSLGK
110 120 130 140 150
QKVFIIRKSL LDELMEVQHF RTIYHMFIAG LCVFIISTLA IDFIDEGRLL
160 170 180 190 200
LEFDLLIFSF GQLPLALVTW VPMFLSTLLA PYQALRLWAR GTWTQATGLG
210 220 230 240 250
CALLAAHAVV LCALPVHVAV EHQLPPASRC VLVFEQVRFL MKSYSFLREA
260 270 280 290 300
VPGTLRARRG EGIQAPSFSS YLYFLFCPTL IYRETYPRTP YVRWNYVAKN
310 320 330 340 350
FAQALGCVLY ACFILGRLCV PVFANMSREP FSTRALVLSI LHATLPGIFM
360 370 380 390 400
LLLIFFAFLH CWLNAFAEML RFGDRMFYRD WWNSTSFSNY YRTWNVVVHD
410 420 430 440 450
WLYSYVYQDG LRLLGARARG VAMLGVFLVS AVAHEYIFCF VLGFFYPVML
460 470 480 490 500
ILFLVIGGML NFMMHDQRTG PAWNVLMWTM LFLGQGIQVS LYCQEWYARR
510 520
HCPLPQATFW GLVTPRSWSC HT
Computationally mapped potential isoform sequencesi
There is 1 potential isoform mapped to this entry.BLASTAlignShow allAdd to basketF8VPE9 | F8VPE9_HUMAN | Sterol O-acyltransferase 2 | SOAT2 | 170 | Annotation score: |
Experimental Info
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Sequence conflicti | 22 | R → P in AAK48829 (PubMed:11401500).Curated | 1 |
Natural variant
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Natural variantiVAR_020373 | 14 | E → G1 PublicationCorresponds to variant dbSNP:rs9658625Ensembl. | 1 | |
Natural variantiVAR_020374 | 254 | T → I2 PublicationsCorresponds to variant dbSNP:rs2272296Ensembl. | 1 |
Alternative sequence
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Alternative sequenceiVSP_057158 | 93 – 148 | Missing in isoform 3. 1 PublicationAdd BLAST | 56 | |
Alternative sequenceiVSP_057159 | 93 – 112 | Missing in isoform 2. 1 PublicationAdd BLAST | 20 | |
Alternative sequenceiVSP_057160 | 236 – 261 | Missing in isoform 3. 1 PublicationAdd BLAST | 26 | |
Alternative sequenceiVSP_057161 | 289 – 310 | TPYVR…GCVLY → PWDVCSMPASSWAASVFLSL PT in isoform 4. 1 PublicationAdd BLAST | 22 | |
Alternative sequenceiVSP_057162 | 311 – 522 | Missing in isoform 4. 1 PublicationAdd BLAST | 212 |
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | AF059203 mRNA Translation: AAC63998.1 AF099031 mRNA Translation: AAC78335.2 AF331516 , AF331502, AF331503, AF331504, AF331505, AF331506, AF331507, AF331508, AF331509, AF331510, AF331511, AF331512, AF331513, AF331514, AF331515 Genomic DNA Translation: AAK18275.1 AF332858, AF332857 Genomic DNA Translation: AAK48829.1 AC073573 Genomic DNA No translation available. BC096090 mRNA Translation: AAH96090.1 BC096091 mRNA Translation: AAH96091.1 BC096092 mRNA Translation: AAH96092.1 BC099626 mRNA Translation: AAH99626.1 |
CCDSi | CCDS8847.1 [O75908-1] |
RefSeqi | NP_003569.1, NM_003578.3 [O75908-1] |
Genome annotation databases
Ensembli | ENST00000301466.8; ENSP00000301466.3; ENSG00000167780.12 ENST00000542365.1; ENSP00000442234.1; ENSG00000167780.12 [O75908-4] |
GeneIDi | 8435 |
KEGGi | hsa:8435 |
MANE-Selecti | ENST00000301466.8; ENSP00000301466.3; NM_003578.4; NP_003569.1 |
UCSCi | uc001sbv.4, human [O75908-1] |
Keywords - Coding sequence diversityi
Alternative splicingSimilar proteinsi
Cross-referencesi
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | AF059203 mRNA Translation: AAC63998.1 AF099031 mRNA Translation: AAC78335.2 AF331516 , AF331502, AF331503, AF331504, AF331505, AF331506, AF331507, AF331508, AF331509, AF331510, AF331511, AF331512, AF331513, AF331514, AF331515 Genomic DNA Translation: AAK18275.1 AF332858, AF332857 Genomic DNA Translation: AAK48829.1 AC073573 Genomic DNA No translation available. BC096090 mRNA Translation: AAH96090.1 BC096091 mRNA Translation: AAH96091.1 BC096092 mRNA Translation: AAH96092.1 BC099626 mRNA Translation: AAH99626.1 |
CCDSi | CCDS8847.1 [O75908-1] |
RefSeqi | NP_003569.1, NM_003578.3 [O75908-1] |
3D structure databases
Select the link destinations: PDBei RCSB PDBi PDBji Links Updated | PDB entry | Method | Resolution (Å) | Chain | Positions | PDBsum |
7N6Q | electron microscopy | 3.87 | A/B/C/D | 2-522 | [»] | |
7N6R | electron microscopy | 3.93 | A/B/C/D | 2-522 | [»] | |
AlphaFoldDBi | O75908 | |||||
SMRi | O75908 | |||||
ModBasei | Search... | |||||
PDBe-KBi | Search... |
Protein-protein interaction databases
BioGRIDi | 114015, 5 interactors |
IntActi | O75908, 3 interactors |
MINTi | O75908 |
STRINGi | 9606.ENSP00000301466 |
Chemistry databases
BindingDBi | O75908 |
ChEMBLi | CHEMBL4465 |
DrugBanki | DB01094, Hesperetin |
SwissLipidsi | SLP:000001262 [O75908-1] |
Protein family/group databases
TCDBi | 2.A.50.4.11, the glycerol uptake (gup) or membrane-bound acyl transferase (mboat) family |
PTM databases
iPTMneti | O75908 |
PhosphoSitePlusi | O75908 |
SwissPalmi | O75908 |
Genetic variation databases
BioMutai | SOAT2 |
Proteomic databases
MassIVEi | O75908 |
PaxDbi | O75908 |
PeptideAtlasi | O75908 |
PRIDEi | O75908 |
ProteomicsDBi | 27608 50258 [O75908-1] |
Protocols and materials databases
Antibodypediai | 43294, 142 antibodies from 21 providers |
DNASUi | 8435 |
Genome annotation databases
Ensembli | ENST00000301466.8; ENSP00000301466.3; ENSG00000167780.12 ENST00000542365.1; ENSP00000442234.1; ENSG00000167780.12 [O75908-4] |
GeneIDi | 8435 |
KEGGi | hsa:8435 |
MANE-Selecti | ENST00000301466.8; ENSP00000301466.3; NM_003578.4; NP_003569.1 |
UCSCi | uc001sbv.4, human [O75908-1] |
Organism-specific databases
CTDi | 8435 |
DisGeNETi | 8435 |
GeneCardsi | SOAT2 |
HGNCi | HGNC:11178, SOAT2 |
HPAi | ENSG00000167780, Tissue enriched (intestine) |
MIMi | 601311, gene |
neXtProti | NX_O75908 |
OpenTargetsi | ENSG00000167780 |
PharmGKBi | PA36016 |
VEuPathDBi | HostDB:ENSG00000167780 |
GenAtlasi | Search... |
Phylogenomic databases
eggNOGi | KOG0380, Eukaryota |
GeneTreei | ENSGT00950000183081 |
HOGENOMi | CLU_031845_1_0_1 |
InParanoidi | O75908 |
OMAi | MHDRHTG |
OrthoDBi | 1275897at2759 |
PhylomeDBi | O75908 |
TreeFami | TF315226 |
Enzyme and pathway databases
BRENDAi | 2.3.1.26, 2681 |
PathwayCommonsi | O75908 |
Reactomei | R-HSA-8964038, LDL clearance |
SABIO-RKi | O75908 |
SignaLinki | O75908 |
Miscellaneous databases
BioGRID-ORCSi | 8435, 18 hits in 1068 CRISPR screens |
GeneWikii | SOAT2 |
GenomeRNAii | 8435 |
Pharosi | O75908, Tchem |
PROi | PR:O75908 |
RNActi | O75908, protein |
SOURCEi | Search... |
Gene expression databases
Bgeei | ENSG00000167780, Expressed in liver and 87 other tissues |
ExpressionAtlasi | O75908, baseline and differential |
Genevisiblei | O75908, HS |
Family and domain databases
InterProi | View protein in InterPro IPR004299, MBOAT_fam IPR014371, Oat_ACAT_DAG_ARE IPR030687, Sterol_acyltranf_meta |
PANTHERi | PTHR10408, PTHR10408, 1 hit |
Pfami | View protein in Pfam PF03062, MBOAT, 1 hit |
PIRSFi | PIRSF000439, Oat_ACAT_DAG_ARE, 1 hit PIRSF500230, Sterol_acyltranf_ACAT, 1 hit |
MobiDBi | Search... |
Entry informationi
Entry namei | SOAT2_HUMAN | |
Accessioni | O75908Primary (citable) accession number: O75908 Secondary accession number(s): F5H7W4 Q9UNR2 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | October 18, 2001 |
Last sequence update: | November 1, 1998 | |
Last modified: | May 25, 2022 | |
This is version 169 of the entry and version 1 of the sequence. See complete history. | ||
Entry statusi | Reviewed (UniProtKB/Swiss-Prot) | |
Annotation program | Chordata Protein Annotation Program | |
Disclaimer | Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. |
Miscellaneousi
Keywords - Technical termi
3D-structure, Reference proteomeDocuments
- Human chromosome 12
Human chromosome 12: entries, gene names and cross-references to MIM - Human entries with genetic variants
List of human entries with genetic variants - Human variants curated from literature reports
Index of human variants curated from literature reports - MIM cross-references
Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot - PDB cross-references
Index of Protein Data Bank (PDB) cross-references - SIMILARITY comments
Index of protein domains and families