UniProtKB - Q9NPI1 (BRD7_HUMAN)
Bromodomain-containing protein 7
BRD7
Functioni
Acts both as coactivator and as corepressor. May play a role in chromatin remodeling. Activator of the Wnt signaling pathway in a DVL1-dependent manner by negatively regulating the GSK3B phosphotransferase activity. Induces dephosphorylation of GSK3B at 'Tyr-216'. Down-regulates TRIM24-mediated activation of transcriptional activation by AR (By similarity).
Transcriptional corepressor that down-regulates the expression of target genes. Binds to target promoters, leading to increased histone H3 acetylation at 'Lys-9' (H3K9ac). Binds to the ESR1 promoter. Recruits BRCA1 and POU2F1 to the ESR1 promoter. Coactivator for TP53-mediated activation of transcription of a set of target genes. Required for TP53-mediated cell-cycle arrest in response to oncogene activation. Promotes acetylation of TP53 at 'Lys-382', and thereby promotes efficient recruitment of TP53 to target promoters. Inhibits cell cycle progression from G1 to S phase.
By similarity5 PublicationsGO - Molecular functioni
- histone binding Source: MGI
- lysine-acetylated histone binding Source: UniProtKB
- p53 binding Source: UniProtKB
- transcription cis-regulatory region binding Source: UniProtKB
- transcription coactivator activity Source: UniProtKB
- transcription corepressor activity Source: UniProtKB
GO - Biological processi
- cell cycle Source: UniProtKB-KW
- negative regulation of cell population proliferation Source: UniProtKB
- negative regulation of G1/S transition of mitotic cell cycle Source: UniProtKB
- negative regulation of transcription, DNA-templated Source: UniProtKB
- positive regulation of histone acetylation Source: UniProtKB
- positive regulation of transcription, DNA-templated Source: UniProtKB
- regulation of transcription by RNA polymerase II Source: MGI
- Wnt signaling pathway Source: UniProtKB-KW
Keywordsi
Biological process | Cell cycle, Transcription, Transcription regulation, Wnt signaling pathway |
Enzyme and pathway databases
PathwayCommonsi | Q9NPI1 |
Reactomei | R-HSA-6804758, Regulation of TP53 Activity through Acetylation |
SignaLinki | Q9NPI1 |
SIGNORi | Q9NPI1 |
Names & Taxonomyi
Protein namesi | Recommended name: Bromodomain-containing protein 7Alternative name(s): 75 kDa bromodomain protein Protein CELTIX-1 |
Gene namesi | Name:BRD7 Synonyms:BP75, CELTIX1 |
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:14310, BRD7 |
MIMi | 618489, gene |
neXtProti | NX_Q9NPI1 |
VEuPathDBi | HostDB:ENSG00000166164 |
Subcellular locationi
Nucleus
Cytosol
- cytosol Source: HPA
Nucleus
- nucleoplasm Source: HPA
- nucleus Source: UniProtKB
Other locations
- cytoplasm Source: ProtInc
Keywords - Cellular componenti
NucleusPathology & Biotechi
Keywords - Diseasei
Tumor suppressorOrganism-specific databases
DisGeNETi | 29117 |
OpenTargetsi | ENSG00000166164 |
PharmGKBi | PA25417 |
Miscellaneous databases
Pharosi | Q9NPI1, Tchem |
Chemistry databases
ChEMBLi | CHEMBL3085622 |
GuidetoPHARMACOLOGYi | 2726 |
Genetic variation databases
BioMutai | BRD7 |
DMDMi | 74734307 |
PTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
ChainiPRO_0000227664 | 1 – 651 | Bromodomain-containing protein 7Add BLAST | 651 |
Amino acid modifications
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Cross-linki | 21 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Cross-linki | 52 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Cross-linki | 127 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Cross-linki | 186 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Cross-linki | 197 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Cross-linki | 201 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Cross-linki | 212 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Cross-linki | 241 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Modified residuei | 279 | PhosphoserineCombined sources | 1 | |
Modified residuei | 289 | PhosphoserineCombined sources | 1 | |
Cross-linki | 305 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Cross-linki | 307 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Modified residuei | 328 | N6-acetyllysineBy similarity | 1 | |
Cross-linki | 344 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Modified residuei | 380 | PhosphoserineCombined sources | 1 | |
Cross-linki | 389 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2)Combined sources | ||
Modified residuei | 482 | PhosphoserineBy similarity | 1 | |
Modified residuei | 514 | PhosphothreonineCombined sources | 1 | |
Modified residuei | 621 | PhosphoserineCombined sources | 1 |
Keywords - PTMi
Acetylation, Isopeptide bond, Phosphoprotein, Ubl conjugationProteomic databases
EPDi | Q9NPI1 |
jPOSTi | Q9NPI1 |
MassIVEi | Q9NPI1 |
MaxQBi | Q9NPI1 |
PaxDbi | Q9NPI1 |
PeptideAtlasi | Q9NPI1 |
PRIDEi | Q9NPI1 |
ProteomicsDBi | 82017 [Q9NPI1-1] 82018 [Q9NPI1-2] |
PTM databases
GlyGeni | Q9NPI1, 1 site, 1 O-linked glycan (1 site) |
iPTMneti | Q9NPI1 |
MetOSitei | Q9NPI1 |
PhosphoSitePlusi | Q9NPI1 |
Expressioni
Gene expression databases
Bgeei | ENSG00000166164, Expressed in testis and 179 other tissues |
ExpressionAtlasi | Q9NPI1, baseline and differential |
Genevisiblei | Q9NPI1, HS |
Organism-specific databases
HPAi | ENSG00000166164, Low tissue specificity |
Interactioni
Subunit structurei
Interacts with TRIM24, PTPN13 and DVL1.
Identified in a complex with SMARCA4/BRG1, SMARCC1/BAF155, SMARCE1/BAF57, DPF2/BAF45D and ARID2, subunits of the SWI/SNF-B (PBAF) chromatin remodeling complex (By similarity).
Interacts with IRF2 and HNRPUL1.
Interacts (via N-terminus) with TP53.
Interacts (via C-terminus) with EP300.
Interacts with BRCA1.
Interacts (via bromo domain) with histone H3 (via N-terminus) acetylated at 'Lys-14' (H3K14ac). Has low affinity for histone H3 acetylated at 'Lys-9' (H3K9ac). Has the highest affinity for histone H3 that is acetylated both at 'Lys-9' (H3K9ac) and at 'Lys-14' (H3K14ac). Has very low affinity for non-acetylated histone H3.
Interacts (via bromo domain) with histone H4 (via N-terminus) acetylated at 'Lys-8' (H3K8ac) (in vitro).
By similarity7 PublicationsBinary interactionsi
Q9NPI1
With | #Exp. | IntAct |
---|---|---|
EP300 [Q09472] | 3 | EBI-711221,EBI-447295 |
HNRNPUL1 [Q9BUJ2] | 5 | EBI-711221,EBI-1018153 |
PLEKHF2 [Q9H8W4] | 3 | EBI-711221,EBI-742388 |
TP53 [P04637] | 9 | EBI-711221,EBI-366083 |
GO - Molecular functioni
- histone binding Source: MGI
- lysine-acetylated histone binding Source: UniProtKB
- p53 binding Source: UniProtKB
Protein-protein interaction databases
BioGRIDi | 118883, 563 interactors |
ComplexPortali | CPX-1196, Polybromo-associated SWI/SNF ATP-dependent chromatin remodeling complex, ACTL6B variant CPX-1199, Polybromo-associated SWI/SNF ATP-dependent chromatin remodeling complex, ACTL6A variant |
CORUMi | Q9NPI1 |
DIPi | DIP-32509N |
IntActi | Q9NPI1, 44 interactors |
MINTi | Q9NPI1 |
STRINGi | 9606.ENSP00000378181 |
Chemistry databases
BindingDBi | Q9NPI1 |
Miscellaneous databases
RNActi | Q9NPI1, protein |
Structurei
Secondary structure
3D structure databases
BMRBi | Q9NPI1 |
SMRi | Q9NPI1 |
ModBasei | Search... |
PDBe-KBi | Search... |
Miscellaneous databases
EvolutionaryTracei | Q9NPI1 |
Family & Domainsi
Domains and Repeats
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Domaini | 148 – 218 | BromoPROSITE-ProRule annotationAdd BLAST | 71 |
Region
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Regioni | 35 – 132 | DisorderedSequence analysisAdd BLAST | 98 | |
Regioni | 253 – 301 | DisorderedSequence analysisAdd BLAST | 49 |
Coiled coil
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Coiled coili | 536 – 567 | Sequence analysisAdd BLAST | 32 |
Motif
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Motifi | 65 – 96 | Nuclear localization signal1 PublicationAdd BLAST | 32 |
Compositional bias
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Compositional biasi | 90 – 109 | Basic and acidic residuesSequence analysisAdd BLAST | 20 | |
Compositional biasi | 270 – 301 | Basic and acidic residuesSequence analysisAdd BLAST | 32 |
Keywords - Domaini
Bromodomain, Coiled coilPhylogenomic databases
eggNOGi | KOG1828, Eukaryota |
GeneTreei | ENSGT00950000183170 |
HOGENOMi | CLU_020704_0_1_1 |
InParanoidi | Q9NPI1 |
OMAi | GEDSSCW |
OrthoDBi | 439339at2759 |
PhylomeDBi | Q9NPI1 |
TreeFami | TF106439 |
Family and domain databases
Gene3Di | 1.20.920.10, 1 hit |
InterProi | View protein in InterPro IPR001487, Bromodomain IPR036427, Bromodomain-like_sf IPR021900, DUF3512 |
Pfami | View protein in Pfam PF00439, Bromodomain, 1 hit PF12024, DUF3512, 1 hit |
PRINTSi | PR00503, BROMODOMAIN |
SMARTi | View protein in SMART SM00297, BROMO, 1 hit |
SUPFAMi | SSF47370, SSF47370, 1 hit |
PROSITEi | View protein in PROSITE PS50014, BROMODOMAIN_2, 1 hit |
s (2+)i Sequence
Sequence statusi: Complete.
This entry describes 2 produced by isoformsialternative splicing. AlignAdd to basketThis entry has 2 described isoforms and 2 potential isoforms that are 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
MGKKHKKHKS DKHLYEEYVE KPLKLVLKVG GNEVTELSTG SSGHDSSLFE
60 70 80 90 100
DKNDHDKHKD RKRKKRKKGE KQIPGEEKGR KRRRVKEDKK KRDRDRVENE
110 120 130 140 150
AEKDLQCHAP VRLDLPPEKP LTSSLAKQEE VEQTPLQEAL NQLMRQLQRK
160 170 180 190 200
DPSAFFSFPV TDFIAPGYSM IIKHPMDFST MKEKIKNNDY QSIEELKDNF
210 220 230 240 250
KLMCTNAMIY NKPETIYYKA AKKLLHSGMK ILSQERIQSL KQSIDFMADL
260 270 280 290 300
QKTRKQKDGT DTSQSGEDGG CWQREREDSG DAEAHAFKSP SKENKKKDKD
310 320 330 340 350
MLEDKFKSNN LEREQEQLDR IVKESGGKLT RRLVNSQCEF ERRKPDGTTT
360 370 380 390 400
LGLLHPVDPI VGEPGYCPVR LGMTTGRLQS GVNTLQGFKE DKRNKVTPVL
410 420 430 440 450
YLNYGPYSSY APHYDSTFAN ISKDDSDLIY STYGEDSDLP SDFSIHEFLA
460 470 480 490 500
TCQDYPYVMA DSLLDVLTKG GHSRTLQEME MSLPEDEGHT RTLDTAKEME
510 520 530 540 550
ITEVEPPGRL DSSTQDRLIA LKAVTNFGVP VEVFDSEEAE IFQKKLDETT
560 570 580 590 600
RLLRELQEAQ NERLSTRPPP NMICLLGPSY REMHLAEQVT NNLKELAQQV
610 620 630 640 650
TPGDIVSTYG VRKAMGISIP SPVMENNFVD LTEDTEEPKK TDVAECGPGG
S
Computationally mapped potential isoform sequencesi
There are 2 potential isoforms mapped to this entry.BLASTAlignShow allAdd to basketI3L0Y7 | I3L0Y7_HUMAN | Bromodomain-containing protein 7 | BRD7 | 32 | Annotation score: | ||
I3L4V5 | I3L4V5_HUMAN | Bromodomain-containing protein 7 | BRD7 | 109 | Annotation score: |
Sequence cautioni
Experimental Info
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Sequence conflicti | 66 | R → G in AAF19526 (PubMed:11025449).Curated | 1 | |
Sequence conflicti | 83 | R → T in AAF19526 (PubMed:11025449).Curated | 1 | |
Sequence conflicti | 96 | R → Q in AAF19526 (PubMed:11025449).Curated | 1 | |
Sequence conflicti | 170 | M → I in AAH94706 (PubMed:15489334).Curated | 1 | |
Sequence conflicti | 485 | E → G in BAB55031 (PubMed:14702039).Curated | 1 |
Alternative sequence
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Alternative sequenceiVSP_017564 | 500 | E → EQ in isoform 2. 2 Publications | 1 |
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | AF213969 mRNA Translation: AAF19526.1 AJ271881 mRNA Translation: CAB72445.1 AF152604 mRNA Translation: AAF75126.1 BC001611 mRNA Translation: AAH01611.1 Different initiation. AC007493 Genomic DNA No translation available. AC007597 Genomic DNA No translation available. AC023826 Genomic DNA No translation available. BC050728 mRNA Translation: AAH50728.1 BC094706 mRNA Translation: AAH94706.1 AK027308 mRNA Translation: BAB55031.1 Different initiation. AK074613 mRNA Translation: BAC11089.1 Different initiation. |
CCDSi | CCDS10742.1 [Q9NPI1-1] CCDS54007.1 [Q9NPI1-2] |
RefSeqi | NP_001167455.1, NM_001173984.2 [Q9NPI1-2] NP_037395.2, NM_013263.4 [Q9NPI1-1] |
Genome annotation databases
Ensembli | ENST00000394688; ENSP00000378180; ENSG00000166164 ENST00000394689; ENSP00000378181; ENSG00000166164 [Q9NPI1-2] |
GeneIDi | 29117 |
KEGGi | hsa:29117 |
MANE-Selecti | ENST00000394688.8; ENSP00000378180.3; NM_013263.5; NP_037395.2 |
UCSCi | uc002ege.3, human [Q9NPI1-1] |
Keywords - Coding sequence diversityi
Alternative splicingSimilar proteinsi
Cross-referencesi
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | AF213969 mRNA Translation: AAF19526.1 AJ271881 mRNA Translation: CAB72445.1 AF152604 mRNA Translation: AAF75126.1 BC001611 mRNA Translation: AAH01611.1 Different initiation. AC007493 Genomic DNA No translation available. AC007597 Genomic DNA No translation available. AC023826 Genomic DNA No translation available. BC050728 mRNA Translation: AAH50728.1 BC094706 mRNA Translation: AAH94706.1 AK027308 mRNA Translation: BAB55031.1 Different initiation. AK074613 mRNA Translation: BAC11089.1 Different initiation. |
CCDSi | CCDS10742.1 [Q9NPI1-1] CCDS54007.1 [Q9NPI1-2] |
RefSeqi | NP_001167455.1, NM_001173984.2 [Q9NPI1-2] NP_037395.2, NM_013263.4 [Q9NPI1-1] |
3D structure databases
Select the link destinations: PDBei RCSB PDBi PDBji Links Updated | PDB entry | Method | Resolution (Å) | Chain | Positions | PDBsum |
2I7K | NMR | - | A | 129-236 | [»] | |
5MQ1 | X-ray | 1.50 | A | 128-239 | [»] | |
6PPA | X-ray | 1.77 | A | 130-250 | [»] | |
6V0Q | X-ray | 1.69 | A/B/C/D | 130-250 | [»] | |
6V16 | X-ray | 1.90 | A/B | 130-250 | [»] | |
6V17 | X-ray | 2.05 | A/B | 130-250 | [»] | |
6V1E | X-ray | 2.30 | A | 129-250 | [»] | |
6V1F | X-ray | 2.00 | A | 129-250 | [»] | |
6V1H | X-ray | 1.93 | A | 129-250 | [»] | |
BMRBi | Q9NPI1 | |||||
SMRi | Q9NPI1 | |||||
ModBasei | Search... | |||||
PDBe-KBi | Search... |
Protein-protein interaction databases
BioGRIDi | 118883, 563 interactors |
ComplexPortali | CPX-1196, Polybromo-associated SWI/SNF ATP-dependent chromatin remodeling complex, ACTL6B variant CPX-1199, Polybromo-associated SWI/SNF ATP-dependent chromatin remodeling complex, ACTL6A variant |
CORUMi | Q9NPI1 |
DIPi | DIP-32509N |
IntActi | Q9NPI1, 44 interactors |
MINTi | Q9NPI1 |
STRINGi | 9606.ENSP00000378181 |
Chemistry databases
BindingDBi | Q9NPI1 |
ChEMBLi | CHEMBL3085622 |
GuidetoPHARMACOLOGYi | 2726 |
PTM databases
GlyGeni | Q9NPI1, 1 site, 1 O-linked glycan (1 site) |
iPTMneti | Q9NPI1 |
MetOSitei | Q9NPI1 |
PhosphoSitePlusi | Q9NPI1 |
Genetic variation databases
BioMutai | BRD7 |
DMDMi | 74734307 |
Proteomic databases
EPDi | Q9NPI1 |
jPOSTi | Q9NPI1 |
MassIVEi | Q9NPI1 |
MaxQBi | Q9NPI1 |
PaxDbi | Q9NPI1 |
PeptideAtlasi | Q9NPI1 |
PRIDEi | Q9NPI1 |
ProteomicsDBi | 82017 [Q9NPI1-1] 82018 [Q9NPI1-2] |
Protocols and materials databases
ABCDi | Q9NPI1, 1 sequenced antibody |
Antibodypediai | 14527, 224 antibodies from 32 providers |
DNASUi | 29117 |
Genome annotation databases
Ensembli | ENST00000394688; ENSP00000378180; ENSG00000166164 ENST00000394689; ENSP00000378181; ENSG00000166164 [Q9NPI1-2] |
GeneIDi | 29117 |
KEGGi | hsa:29117 |
MANE-Selecti | ENST00000394688.8; ENSP00000378180.3; NM_013263.5; NP_037395.2 |
UCSCi | uc002ege.3, human [Q9NPI1-1] |
Organism-specific databases
CTDi | 29117 |
DisGeNETi | 29117 |
GeneCardsi | BRD7 |
HGNCi | HGNC:14310, BRD7 |
HPAi | ENSG00000166164, Low tissue specificity |
MIMi | 618489, gene |
neXtProti | NX_Q9NPI1 |
OpenTargetsi | ENSG00000166164 |
PharmGKBi | PA25417 |
VEuPathDBi | HostDB:ENSG00000166164 |
GenAtlasi | Search... |
Phylogenomic databases
eggNOGi | KOG1828, Eukaryota |
GeneTreei | ENSGT00950000183170 |
HOGENOMi | CLU_020704_0_1_1 |
InParanoidi | Q9NPI1 |
OMAi | GEDSSCW |
OrthoDBi | 439339at2759 |
PhylomeDBi | Q9NPI1 |
TreeFami | TF106439 |
Enzyme and pathway databases
PathwayCommonsi | Q9NPI1 |
Reactomei | R-HSA-6804758, Regulation of TP53 Activity through Acetylation |
SignaLinki | Q9NPI1 |
SIGNORi | Q9NPI1 |
Miscellaneous databases
BioGRID-ORCSi | 29117, 91 hits in 1055 CRISPR screens |
ChiTaRSi | BRD7, human |
EvolutionaryTracei | Q9NPI1 |
GeneWikii | BRD7 |
GenomeRNAii | 29117 |
Pharosi | Q9NPI1, Tchem |
PROi | PR:Q9NPI1 |
RNActi | Q9NPI1, protein |
SOURCEi | Search... |
Gene expression databases
Bgeei | ENSG00000166164, Expressed in testis and 179 other tissues |
ExpressionAtlasi | Q9NPI1, baseline and differential |
Genevisiblei | Q9NPI1, HS |
Family and domain databases
Gene3Di | 1.20.920.10, 1 hit |
InterProi | View protein in InterPro IPR001487, Bromodomain IPR036427, Bromodomain-like_sf IPR021900, DUF3512 |
Pfami | View protein in Pfam PF00439, Bromodomain, 1 hit PF12024, DUF3512, 1 hit |
PRINTSi | PR00503, BROMODOMAIN |
SMARTi | View protein in SMART SM00297, BROMO, 1 hit |
SUPFAMi | SSF47370, SSF47370, 1 hit |
PROSITEi | View protein in PROSITE PS50014, BROMODOMAIN_2, 1 hit |
MobiDBi | Search... |
Entry informationi
Entry namei | BRD7_HUMAN | |
Accessioni | Q9NPI1Primary (citable) accession number: Q9NPI1 Secondary accession number(s): Q4VC09 Q9UH59 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | March 21, 2006 |
Last sequence update: | October 1, 2000 | |
Last modified: | February 23, 2022 | |
This is version 173 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 16
Human chromosome 16: entries, gene names and cross-references to MIM - 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