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Protein

Regulatory protein SIR1

Gene

SIR1

Organism
Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Involved in the establishment, but not the maintenance, of heterochromatic silencing at the cryptic mating-type loci HMR and HML. Is recruited by interacting with the ORC1 subunit of the origin recognition complex (ORC), which binds to HML-I or HMR-E silencers, DNA elements that direct the formation of silent chromatin at the mating-type loci. Establishes transcriptional silencing by recruiting the three other SIR proteins, SIR2, SIR3, and SIR4, that function directly in silenced chromatin and establish repression. Also found in centromeric chromatin. Binds to and helps retain CAC1, a subunit of chromatin assembly factor I (CAF-I) at centromeric loci independent on the other SIR proteins.3 Publications

GO - Molecular functioni

  • chromatin binding Source: SGD
  • sequence-specific DNA binding Source: SGD

GO - Biological processi

  • chromatin silencing at silent mating-type cassette Source: SGD
  • establishment of chromatin silencing Source: SGD
  • transcription, DNA-templated Source: UniProtKB-KW
Complete GO annotation...

Keywords - Molecular functioni

Repressor

Keywords - Biological processi

Transcription, Transcription regulation

Enzyme and pathway databases

BioCyciYEAST:G3O-32063-MONOMER.

Names & Taxonomyi

Protein namesi
Recommended name:
Regulatory protein SIR1
Alternative name(s):
Heterochromatin protein SIR1
Silent information regulator 1
Gene namesi
Name:SIR1
Ordered Locus Names:YKR101W
OrganismiSaccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Taxonomic identifieri559292 [NCBI]
Taxonomic lineageiEukaryotaFungiDikaryaAscomycotaSaccharomycotinaSaccharomycetesSaccharomycetalesSaccharomycetaceaeSaccharomyces
Proteomesi
  • UP000002311 Componenti: Chromosome XI

Organism-specific databases

EuPathDBiFungiDB:YKR101W.
SGDiS000001809. SIR1.

Subcellular locationi

GO - Cellular componenti

  • chromatin silencing complex Source: SGD
  • chromosome, centromeric region Source: UniProtKB-SubCell
Complete GO annotation...

Keywords - Cellular componenti

Centromere, Chromosome, Nucleus

Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi462 – 464EEE → AAA: No effect. 1 Publication3
Mutagenesisi466V → G: Abolishes interaction with ORC1. 1 Publication1
Mutagenesisi469R → G: Abolishes interaction with ORC1. 1 Publication1
Mutagenesisi470F → S: Abolishes interaction with ORC1 and SIR4. 1 Publication1
Mutagenesisi477L → P: Abolishes interaction with ORC1 and SIR4. 1 Publication1
Mutagenesisi479D → N: Abolishes interaction with ORC1. 1 Publication1
Mutagenesisi480L → P: Abolishes interaction with ORC1. 1 Publication1
Mutagenesisi482 – 483EE → AA: No effect. 1 Publication2
Mutagenesisi489 – 490KD → AA: No effect. 1 Publication2
Mutagenesisi498 – 499KD → AA: No effect. 1 Publication2
Mutagenesisi513W → R: Abolishes interaction with ORC1 and SIR4. 1 Publication1
Mutagenesisi517 – 518KK → AA: No effect. 1 Publication2
Mutagenesisi534C → A: No effect. 1 Publication1
Mutagenesisi538 – 540KKK → AAA: Abolishes interaction with SIR4. 1 Publication3
Mutagenesisi569C → A: No effect. 1
Mutagenesisi571C → R: Abolishes interaction with ORC1 and SIR4. 1 Publication1
Mutagenesisi572V → G: No effect. 1 Publication1
Mutagenesisi573P → S: No effect. 1 Publication1
Mutagenesisi577 – 578DD → AA: Abolishes interaction with SIR4. 1 Publication2
Mutagenesisi584L → P or Q: Abolishes interaction with ORC1 and SIR4. 1 Publication1
Mutagenesisi586 – 587DD → AA: Abolishes interaction with SIR4. 1 Publication2

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00000977671 – 654Regulatory protein SIR1Add BLAST654

Proteomic databases

MaxQBiP21691.
PRIDEiP21691.

Interactioni

Subunit structurei

Interacts (via OIR domain) with ORC1 (via BAH domain). Interacts with SIR4. Interacts with CAC1.6 Publications

Protein-protein interaction databases

BioGridi34232. 75 interactors.
DIPiDIP-2453N.
IntActiP21691. 3 interactors.
MINTiMINT-518571.

Structurei

Secondary structure

1654
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Beta strandi464 – 473Combined sources10
Beta strandi476 – 479Combined sources4
Turni480 – 483Combined sources4
Beta strandi484 – 486Combined sources3
Helixi493 – 496Combined sources4
Helixi499 – 506Combined sources8
Helixi513 – 516Combined sources4
Beta strandi523 – 525Combined sources3
Helixi530 – 533Combined sources4
Beta strandi537 – 543Combined sources7
Beta strandi547 – 550Combined sources4
Beta strandi566 – 575Combined sources10
Beta strandi577 – 579Combined sources3
Beta strandi581 – 586Combined sources6

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1Z1AX-ray2.50A/B449-587[»]
1ZBXX-ray2.50B456-588[»]
1ZHIX-ray2.70B456-587[»]
ProteinModelPortaliP21691.
SMRiP21691.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP21691.

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni322 – 654Sufficient for interaction with SIR41 PublicationAdd BLAST333
Regioni449 – 587ORC interacting region (OIR)Add BLAST139

Phylogenomic databases

InParanoidiP21691.
KOiK11120.
OMAiNINENYG.
OrthoDBiEOG092C0UBV.

Family and domain databases

InterProiIPR021646. Sir1_ORC-binding.
[Graphical view]
PfamiPF11603. Sir1. 2 hits.
[Graphical view]

Sequencei

Sequence statusi: Complete.

P21691-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MLQINSRLAV IDGWLVDTVK RKPINFRSPE VRLLLPNDDD YKKLSQQNLV
60 70 80 90 100
DWTRLKKDSN SVLVGVKSME LFKHIKLVLR EFFLLEDGRI ILKRIRSKLR
110 120 130 140 150
YKVVKKLTCK CCRLYLPKWG TVYIHPMLKD KEKPLAGVCE FSLDVNPDRE
160 170 180 190 200
YPLIEINVSH QYIIIEGFLL YLNERRLYRW NDNNLRSQVG LTKWAHLRKT
210 220 230 240 250
YNPVSLDILY SLNSNFYFVK DDLLFQLLGK RVFVKFCKVM ENGKCGKAPL
260 270 280 290 300
WYRVKRTTTA KATHIAYAIS NSTAPDSFKS KNNDYRFIVR EKPIVENTIS
310 320 330 340 350
NLDYSDIKKQ QFTEAEVVKR KISADISQIE NVHTQFNSQK EKNNIRVNKV
360 370 380 390 400
SSEVLDQISK FPVSRVTLLL MSAGQDKNYI ELVEELARRL EKICIEKTTQ
410 420 430 440 450
SLEEIRDTFQ ANPEMQASFD KEYYQSIEEY KITLELIKED LLITLIKQME
460 470 480 490 500
NMWAAEKKFS TEEEYVSPRF LVADGFLIDL AEEKPINPKD PRLLTLLKDH
510 520 530 540 550
QRAMIDQMNL VKWNDFKKYQ DPIPLKAKTL FKFCKQIKKK FLRGADFKLH
560 570 580 590 600
TLPTEANLKY EPERMTVLCS CVPILLDDQT VQYLYDDSII PEFEATSSYA
610 620 630 640 650
TKQSKCGRKM SLQMEPDLLF QEAIRRMRHL TAYDVLRRNY IAAFEELYMG

NCND
Length:654
Mass (Da):76,933
Last modified:July 28, 2009 - v2
Checksum:i00FEABD1BD35BC81
GO

Sequence cautioni

The sequence AAA35046 differs from that shown. Reason: Erroneous initiation.Curated
The sequence CAA82181 differs from that shown. Reason: Erroneous initiation.Curated

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M38524 Genomic DNA. Translation: AAA35046.1. Different initiation.
Z28326 Genomic DNA. Translation: CAA82181.1. Different initiation.
BK006944 Genomic DNA. Translation: DAA09252.1.
PIRiS14173.
RefSeqiNP_013027.4. NM_001179891.3.

Genome annotation databases

EnsemblFungiiYKR101W; YKR101W; YKR101W.
GeneIDi853976.
KEGGisce:YKR101W.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M38524 Genomic DNA. Translation: AAA35046.1. Different initiation.
Z28326 Genomic DNA. Translation: CAA82181.1. Different initiation.
BK006944 Genomic DNA. Translation: DAA09252.1.
PIRiS14173.
RefSeqiNP_013027.4. NM_001179891.3.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1Z1AX-ray2.50A/B449-587[»]
1ZBXX-ray2.50B456-588[»]
1ZHIX-ray2.70B456-587[»]
ProteinModelPortaliP21691.
SMRiP21691.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi34232. 75 interactors.
DIPiDIP-2453N.
IntActiP21691. 3 interactors.
MINTiMINT-518571.

Proteomic databases

MaxQBiP21691.
PRIDEiP21691.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblFungiiYKR101W; YKR101W; YKR101W.
GeneIDi853976.
KEGGisce:YKR101W.

Organism-specific databases

EuPathDBiFungiDB:YKR101W.
SGDiS000001809. SIR1.

Phylogenomic databases

InParanoidiP21691.
KOiK11120.
OMAiNINENYG.
OrthoDBiEOG092C0UBV.

Enzyme and pathway databases

BioCyciYEAST:G3O-32063-MONOMER.

Miscellaneous databases

EvolutionaryTraceiP21691.
PROiP21691.

Family and domain databases

InterProiIPR021646. Sir1_ORC-binding.
[Graphical view]
PfamiPF11603. Sir1. 2 hits.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiSIR1_YEAST
AccessioniPrimary (citable) accession number: P21691
Secondary accession number(s): D6VXG2
Entry historyi
Integrated into UniProtKB/Swiss-Prot: May 1, 1991
Last sequence update: July 28, 2009
Last modified: November 2, 2016
This is version 124 of the entry and version 2 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programFungal Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  2. Yeast
    Yeast (Saccharomyces cerevisiae): entries, gene names and cross-references to SGD
  3. Yeast chromosome XI
    Yeast (Saccharomyces cerevisiae) chromosome XI: entries and gene names

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.