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Protein

Ribosome-associated molecular chaperone SSB1

Gene

SSB1

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

Ribosome-bound, Hsp70-type chaperone that assists in the cotranslational folding of newly synthesized proteins in the cytosol. Stimulates folding by interacting with nascent chains, binding to short, largely hydrophobic sequences exposed by unfolded proteins, thereby stabilizing longer, more slowly translated, and aggregation-prone nascent polypeptides and domains that cannot fold stably until fully synthesized. The Hsp70-protein substrate interaction depends on ATP-binding and on allosteric regulation between the NBD and the SBD. The ATP-bound state is characterized by a fast exchange rate of substrate (low affinity state), while in the ADP-bound state exchange is much slower (high affinity state). During the Hsp70 cycle, the chaperone switches between the ATP-bound state (open conformation) and the ADP-bound state (closed conformation) by major conformational rearrangements involving mainly the lid domain. Ssb cooperates with a specific Hsp40/Hsp70 co-chaperone termed the ribosome-associated complex (RAC), which stimulates the ATPase activity of the ribosome-associated pool of Ssbs and switches it to the high affinity substrate binding state. Hsp110 chaperone SSE1 and FES1 act as nucleotide exchange factors that cause substrate release.8 Publications

Miscellaneous

Present with 170000 molecules/cell in log phase SD medium.1 Publication

Catalytic activityi

ATP + H2O = ADP + phosphate.1 Publication

Kineticsi

kcat is 0.95 min(-1) with ATP as substrate (at 2.5 mM potassium acetate) and 0.81 min(-1) with ATP as substrate (at 100 mM potassium acetate).1 Publication
  1. KM=270 µM for ATP (at 2.5 mM potassium acetate)1 Publication
  2. KM=147 µM for ATP (at 100 mM potassium acetate)1 Publication

    Sites

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Binding sitei73ATPBy similarity1
    Binding sitei342ATP; via amide nitrogenBy similarity1

    Regions

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Nucleotide bindingi16 – 18ATPBy similarity3
    Nucleotide bindingi205 – 207ATPBy similarity3
    Nucleotide bindingi271 – 278ATPBy similarity8

    GO - Molecular functioni

    • ATPase activity Source: SGD
    • ATP binding Source: UniProtKB-KW
    • calmodulin binding Source: SGD
    • unfolded protein binding Source: SGD

    GO - Biological processi

    • 'de novo' cotranslational protein folding Source: SGD
    • cellular response to glucose starvation Source: SGD
    • cytoplasmic translation Source: SGD
    • regulation of translational fidelity Source: SGD
    • ribosomal subunit export from nucleus Source: SGD
    • rRNA processing Source: SGD
    • translational frameshifting Source: SGD
    • translational termination Source: SGD

    Keywordsi

    Molecular functionChaperone, Hydrolase
    Biological processProtein biosynthesis
    LigandATP-binding, Nucleotide-binding

    Enzyme and pathway databases

    BioCyciYEAST:G3O-29608-MONOMER.

    Names & Taxonomyi

    Protein namesi
    Recommended name:
    Ribosome-associated molecular chaperone SSB11 Publication (EC:3.6.4.101 Publication)
    Alternative name(s):
    Cold-inducible protein YG1011 Publication
    Heat shock protein SSB11 Publication
    Hsp70 chaperone Ssb1 Publication
    Gene namesi
    Name:SSB11 Publication
    Synonyms:YG1011 Publication
    Ordered Locus Names:YDL229WImported
    OrganismiSaccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
    Taxonomic identifieri559292 [NCBI]
    Taxonomic lineageiEukaryotaFungiDikaryaAscomycotaSaccharomycotinaSaccharomycetesSaccharomycetalesSaccharomycetaceaeSaccharomyces
    Proteomesi
    • UP000002311 Componenti: Chromosome IV

    Organism-specific databases

    EuPathDBiFungiDB:YDL229W.
    SGDiS000002388. SSB1.

    Subcellular locationi

    Keywords - Cellular componenti

    Cytoplasm

    Pathology & Biotechi

    Mutagenesis

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Mutagenesisi73K → A: Unable to hydrolyze ATP and moderately reduces ribosome binding. 1 Publication1
    Mutagenesisi567 – 568KR → EE in SSB1-L(BC): Reduces ribosome-binding to less than 50%. 1 Publication2
    Mutagenesisi596 – 597RK → DD in SSB1-D1: Reduces ribosome-binding to less than 50%. 1 Publication2
    Mutagenesisi603 – 604KR → DD in SSB1-D2: Reduces ribosome-binding to less than 50%. 1 Publication2

    PTM / Processingi

    Molecule processing

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Initiator methionineiRemoved1 Publication
    ChainiPRO_00000783892 – 613Ribosome-associated molecular chaperone SSB1Add BLAST612

    Amino acid modifications

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Modified residuei2N-acetylalanine1 Publication1
    Modified residuei47PhosphothreonineCombined sources1
    Modified residuei431PhosphothreonineCombined sources1

    Keywords - PTMi

    Acetylation, Phosphoprotein

    Proteomic databases

    MaxQBiP11484.
    PRIDEiP11484.
    TopDownProteomicsiP11484.

    2D gel databases

    COMPLUYEAST-2DPAGEiP11484.
    SWISS-2DPAGEiP11484.
    UCD-2DPAGEiP11484.

    PTM databases

    iPTMnetiP11484.

    Expressioni

    Inductioni

    Expression decreases after heat shock or during growth to stationary phase (PubMed:6761581, PubMed:2651414). Degraded during heat shock treatment (at protein level) (PubMed:7646503). Up-regulated upon carbon upshift and down-regulated upon amino acid limitation in an HSF1-dependent manner (PubMed:10322015).4 Publications

    Interactioni

    Subunit structurei

    Binds to ribosomes (PubMed:9670014, PubMed:1394434, PubMed:27917864). Binds close to the ribosomal tunnel exit via contacts with both ribosomal proteins RPL35, RPL39 and RPL19, and rRNA (PubMed:27882919). Directly interacts with nascent polypeptides. This interaction is dependent on the ribosome-associated complex (RAC) (PubMed:11929994, PubMed:23332755). Interacts with SSE1 (PubMed:16219770, PubMed:16221677, PubMed:23332755). Interacts with FES1 (PubMed:17132105). Interacts with NAP1 (PubMed:18086883).10 Publications

    Binary interactionsi

    WithEntry#Exp.IntActNotes
    ADE16P541133EBI-8627,EBI-14213
    ADE3P072453EBI-8627,EBI-3897
    AHA1Q124493EBI-8627,EBI-37072
    APE2P324544EBI-8627,EBI-2641
    ARO1P085663EBI-8627,EBI-2883
    ASF1P324473EBI-8627,EBI-3003
    BET3P361493EBI-8627,EBI-3567
    BLM10P435832EBI-8627,EBI-22761
    BRR2P326393EBI-8627,EBI-861
    BRX1Q082353EBI-8627,EBI-3775
    BUD27P435735EBI-8627,EBI-22787
    BZZ1P388223EBI-8627,EBI-3889
    CAF40P538293EBI-8627,EBI-28306
    CAM1P295473EBI-8627,EBI-6323
    CCL1P373663EBI-8627,EBI-4385
    CDC27P380423EBI-8627,EBI-4249
    CDC28P005463EBI-8627,EBI-4253
    CDC55Q003623EBI-8627,EBI-1942
    CHD1P326573EBI-8627,EBI-4574
    CHS5Q121143EBI-8627,EBI-4640
    CKA1P157903EBI-8627,EBI-9533
    CKA2P194543EBI-8627,EBI-9548
    CRM1P308223EBI-8627,EBI-20589
    CTK2P469623EBI-8627,EBI-5236
    CWC22P533333EBI-8627,EBI-565
    DBP2P247833EBI-8627,EBI-5602
    DBP6P537343EBI-8627,EBI-5625
    DBP8P387193EBI-8627,EBI-5633
    DCP2P535503EBI-8627,EBI-270
    DIS3Q081623EBI-8627,EBI-1740
    DNA2P388593EBI-8627,EBI-5973
    DNM1P548613EBI-8627,EBI-6002
    EAF3Q124323EBI-8627,EBI-6281
    ECM16Q042173EBI-8627,EBI-1820
    ECM29P387373EBI-8627,EBI-24359
    EIS1Q050503EBI-8627,EBI-28061
    EMW1P428423EBI-8627,EBI-28374
    ENO1P009243EBI-8627,EBI-6468
    FAR1P212683EBI-8627,EBI-6780
    FIP1P459763EBI-8627,EBI-6940
    GLC3P327753EBI-8627,EBI-7652
    GLC7P325983EBI-8627,EBI-13715
    GPT2P361483EBI-8627,EBI-26471
    HAT1Q123413EBI-8627,EBI-8176
    HHF2P023093EBI-8627,EBI-8113
    HMO1Q039733EBI-8627,EBI-33047
    HOS4P404803EBI-8627,EBI-8492
    HSC82P151083EBI-8627,EBI-8666
    HSP82P028293EBI-8627,EBI-8659
    HTB2P022943EBI-8627,EBI-8094
    IPI1P388033EBI-8627,EBI-24606
    JSN1P471353EBI-8627,EBI-9422
    KAP95Q061423EBI-8627,EBI-9145
    KIN1P131853EBI-8627,EBI-9716
    KRE33P539143EBI-8627,EBI-28914
    LPD1P096243EBI-8627,EBI-5940
    LSM4P400703EBI-8627,EBI-188
    MAK21Q121763EBI-8627,EBI-10944
    MAM3Q122963EBI-8627,EBI-33338
    MAM33P405133EBI-8627,EBI-10316
    MAS2P119143EBI-8627,EBI-11205
    MCM2P294692EBI-8627,EBI-10533
    MCM5P294963EBI-8627,EBI-10549
    MDR1P532583EBI-8627,EBI-10889
    MET18P404693EBI-8627,EBI-11492
    MET5P471693EBI-8627,EBI-25702
    MFT1P334413EBI-8627,EBI-10841
    MRD1Q061063EBI-8627,EBI-34383
    MRP1P106624EBI-8627,EBI-16234
    MSH6Q038343EBI-8627,EBI-11383
    NAM9P279293EBI-8627,EBI-11843
    NEW1Q089723EBI-8627,EBI-32014
    NOP13P538833EBI-8627,EBI-29032
    NTH1P323563EBI-8627,EBI-19509
    NUP1P206764EBI-8627,EBI-12392
    NUP2P324993EBI-8627,EBI-12401
    OCA5P387383EBI-8627,EBI-24355
    ORC6P388263EBI-8627,EBI-12588
    PFK26P404333EBI-8627,EBI-1956
    PRT1P061033EBI-8627,EBI-8973
    PTC2P399663EBI-8627,EBI-12795
    PWP1P213044EBI-8627,EBI-14328
    PXL1P361663EBI-8627,EBI-26535
    RAD52P067783EBI-8627,EBI-14719
    RCO1Q047793EBI-8627,EBI-28153
    RET1P222763EBI-8627,EBI-15815
    RFX1P487433EBI-8627,EBI-15036
    RPA190P109643EBI-8627,EBI-15730
    RPC34P329103EBI-8627,EBI-15835
    RPC40P077033EBI-8627,EBI-15831
    RPC82P323493EBI-8627,EBI-15821
    RPF2P361603EBI-8627,EBI-15881
    RPN7Q061033EBI-8627,EBI-15940
    RRP5Q050223EBI-8627,EBI-16011
    RSC2Q064883EBI-8627,EBI-16198
    RSC8P436093EBI-8627,EBI-23005
    RTN1Q049473EBI-8627,EBI-38020
    SAM1P106593EBI-8627,EBI-10789
    SEC7P110753EBI-8627,EBI-16882
    SET2P469953EBI-8627,EBI-16985
    SFB2P539534EBI-8627,EBI-17006
    SIN3P225793EBI-8627,EBI-17160
    SIW14P539653EBI-8627,EBI-28668
    SKI2P352073EBI-8627,EBI-1851
    SMC3P470373EBI-8627,EBI-17423
    SMI1P325663EBI-8627,EBI-17452
    SNF1P067823EBI-8627,EBI-17516
    SNT2P531273EBI-8627,EBI-23958
    SNX41Q040535EBI-8627,EBI-30464
    SSA1P105913EBI-8627,EBI-8591
    SSE1P325894EBI-8627,EBI-8648
    STE20Q034973EBI-8627,EBI-18285
    STH1P325973EBI-8627,EBI-18410
    SVF1Q055153EBI-8627,EBI-38400
    SWA2Q066773EBI-8627,EBI-30084
    SXM1Q041753EBI-8627,EBI-35508
    TEF2P029943EBI-8627,EBI-6314
    TIF2P100813EBI-8627,EBI-9017
    TOP2P067863EBI-8627,EBI-19352
    TSC13Q991903EBI-8627,EBI-31149
    TUB3P097343EBI-8627,EBI-18981
    UBP1P250373EBI-8627,EBI-19819
    UBP2Q014763EBI-8627,EBI-19826
    UTP18P403624EBI-8627,EBI-4534
    UTP21Q060783EBI-8627,EBI-359
    UTP22P532543EBI-8627,EBI-1878
    VIP1Q066853EBI-8627,EBI-35034
    VPS16Q033083EBI-8627,EBI-20355
    WTM1Q123633EBI-8627,EBI-20563
    YCP4P253493EBI-8627,EBI-21840
    YMR027WQ043713EBI-8627,EBI-28049
    YMR099CQ031613EBI-8627,EBI-28203
    YNR029CP537294EBI-8627,EBI-28492
    YOL098CQ124963EBI-8627,EBI-29300
    YPR089WO135853EBI-8627,EBI-33008
    ZDS1P501113EBI-8627,EBI-29626
    ZDS2P547863EBI-8627,EBI-29637

    GO - Molecular functioni

    • calmodulin binding Source: SGD
    • unfolded protein binding Source: SGD

    Protein-protein interaction databases

    BioGridi31882. 772 interactors.
    DIPiDIP-2254N.
    IntActiP11484. 3493 interactors.
    MINTiMINT-1325604.
    STRINGi4932.YDL229W.

    Structurei

    Secondary structure

    1613
    Legend: HelixTurnBeta strandPDB Structure known for this area
    Show more details
    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Beta strandi10 – 13Combined sources4
    Beta strandi16 – 30Combined sources15
    Beta strandi38 – 41Combined sources4
    Beta strandi44 – 46Combined sources3
    Beta strandi51 – 54Combined sources4
    Helixi55 – 59Combined sources5
    Helixi61 – 63Combined sources3
    Helixi65 – 67Combined sources3
    Helixi72 – 74Combined sources3
    Turni75 – 77Combined sources3
    Helixi83 – 89Combined sources7
    Beta strandi93 – 99Combined sources7
    Beta strandi102 – 109Combined sources8
    Beta strandi112 – 116Combined sources5
    Helixi118 – 137Combined sources20
    Beta strandi143 – 148Combined sources6
    Helixi154 – 166Combined sources13
    Beta strandi170 – 176Combined sources7
    Helixi177 – 184Combined sources8
    Turni185 – 190Combined sources6
    Beta strandi196 – 203Combined sources8
    Beta strandi208 – 216Combined sources9
    Beta strandi219 – 228Combined sources10
    Helixi233 – 252Combined sources20
    Helixi260 – 276Combined sources17
    Turni277 – 279Combined sources3
    Beta strandi280 – 291Combined sources12
    Beta strandi294 – 301Combined sources8
    Helixi302 – 308Combined sources7
    Helixi310 – 315Combined sources6
    Helixi317 – 327Combined sources11
    Helixi331 – 333Combined sources3
    Beta strandi336 – 341Combined sources6
    Helixi342 – 345Combined sources4
    Helixi347 – 356Combined sources10
    Turni357 – 359Combined sources3
    Turni368 – 370Combined sources3
    Helixi371 – 383Combined sources13

    3D structure databases

    Select the link destinations:
    PDBei
    RCSB PDBi
    PDBji
    Links Updated
    PDB entryMethodResolution (Å)ChainPositionsPDBsum
    3GL1X-ray1.92A/B1-384[»]
    ProteinModelPortaliP11484.
    SMRiP11484.
    ModBaseiSearch...
    MobiDBiSearch...

    Miscellaneous databases

    EvolutionaryTraceiP11484.

    Family & Domainsi

    Region

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Regioni2 – 391Nucleotide binding domain (NBD)By similarityAdd BLAST390
    Regioni392 – 402Inter-domain linkerBy similarityAdd BLAST11
    Regioni403 – 613Substrate binding domain (SBD)By similarityAdd BLAST211
    Regioni516 – 612Lid domain (SBDalpha)By similarityAdd BLAST97
    Regioni601 – 613Required for interaction with ribosomes1 PublicationAdd BLAST13

    Motif

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Motifi428 – 430Contributes to ribosome binding1 Publication3
    Motifi574 – 582Nuclear export signal1 Publication9

    Sequence similaritiesi

    Phylogenomic databases

    GeneTreeiENSGT00890000139776.
    HOGENOMiHOG000228135.
    InParanoidiP11484.
    OMAiFEEINST.
    OrthoDBiEOG092C1VPN.

    Family and domain databases

    Gene3Di1.20.1270.10. 1 hit.
    2.60.34.10. 1 hit.
    InterProiView protein in InterPro
    IPR018181. Heat_shock_70_CS.
    IPR029048. HSP70_C.
    IPR029047. HSP70_peptide-bd.
    IPR013126. Hsp_70_fam.
    PfamiView protein in Pfam
    PF00012. HSP70. 1 hit.
    PRINTSiPR00301. HEATSHOCK70.
    SUPFAMiSSF100920. SSF100920. 1 hit.
    SSF100934. SSF100934. 1 hit.
    PROSITEiView protein in PROSITE
    PS00297. HSP70_1. 1 hit.
    PS00329. HSP70_2. 1 hit.
    PS01036. HSP70_3. 1 hit.

    Sequencei

    Sequence statusi: Complete.

    Sequence processingi: The displayed sequence is further processed into a mature form.

    P11484-1 [UniParc]FASTAAdd to basket

    « Hide

            10         20         30         40         50
    MAEGVFQGAI GIDLGTTYSC VATYESSVEI IANEQGNRVT PSFVAFTPEE
    60 70 80 90 100
    RLIGDAAKNQ AALNPRNTVF DAKRLIGRRF DDESVQKDMK TWPFKVIDVD
    110 120 130 140 150
    GNPVIEVQYL EETKTFSPQE ISAMVLTKMK EIAEAKIGKK VEKAVITVPA
    160 170 180 190 200
    YFNDAQRQAT KDAGAISGLN VLRIINEPTA AAIAYGLGAG KSEKERHVLI
    210 220 230 240 250
    FDLGGGTFDV SLLHIAGGVY TVKSTSGNTH LGGQDFDTNL LEHFKAEFKK
    260 270 280 290 300
    KTGLDISDDA RALRRLRTAA ERAKRTLSSV TQTTVEVDSL FDGEDFESSL
    310 320 330 340 350
    TRARFEDLNA ALFKSTLEPV EQVLKDAKIS KSQIDEVVLV GGSTRIPKVQ
    360 370 380 390 400
    KLLSDFFDGK QLEKSINPDE AVAYGAAVQG AILTGQSTSD ETKDLLLLDV
    410 420 430 440 450
    APLSLGVGMQ GDMFGIVVPR NTTVPTIKRR TFTTCADNQT TVQFPVYQGE
    460 470 480 490 500
    RVNCKENTLL GEFDLKNIPM MPAGEPVLEA IFEVDANGIL KVTAVEKSTG
    510 520 530 540 550
    KSSNITISNA VGRLSSEEIE KMVNQAEEFK AADEAFAKKH EARQRLESYV
    560 570 580 590 600
    ASIEQTVTDP VLSSKLKRGS KSKIEAALSD ALAALQIEDP SADELRKAEV
    610
    GLKRVVTKAM SSR
    Length:613
    Mass (Da):66,602
    Last modified:January 23, 2007 - v3
    Checksum:iF16FA7C25A40321A
    GO

    Experimental Info

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Sequence conflicti180 – 184AAAIA → VVVIV in AAA34692 (PubMed:6761581).Curated5
    Sequence conflicti189A → V in AAA34692 (PubMed:6761581).Curated1
    Sequence conflicti192S → F in AAA34692 (PubMed:6761581).Curated1

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    X13713 Genomic DNA. Translation: CAA31995.1.
    M25395 mRNA. Translation: AAA35099.1.
    Z74277 Genomic DNA. Translation: CAA98807.1.
    M17585 Genomic DNA. Translation: AAA34692.1.
    BK006938 Genomic DNA. Translation: DAA11637.1.
    PIRiS20149.
    RefSeqiNP_010052.1. NM_001180289.1.

    Genome annotation databases

    EnsemblFungiiYDL229W; YDL229W; YDL229W.
    GeneIDi851369.
    KEGGisce:YDL229W.

    Similar proteinsi

    Entry informationi

    Entry nameiSSB1_YEAST
    AccessioniPrimary (citable) accession number: P11484
    Secondary accession number(s): D6VRC7, Q05834
    Entry historyiIntegrated into UniProtKB/Swiss-Prot: October 1, 1989
    Last sequence update: January 23, 2007
    Last modified: September 27, 2017
    This is version 177 of the entry and version 3 of the sequence. See complete history.
    Entry statusiReviewed (UniProtKB/Swiss-Prot)
    Annotation programFungal Protein Annotation Program

    Miscellaneousi

    Keywords - Technical termi

    3D-structure, Complete proteome, Direct protein sequencing, Reference proteome

    Documents

    1. PDB cross-references
      Index of Protein Data Bank (PDB) cross-references
    2. SIMILARITY comments
      Index of protein domains and families
    3. Yeast
      Yeast (Saccharomyces cerevisiae): entries, gene names and cross-references to SGD
    4. Yeast chromosome IV
      Yeast (Saccharomyces cerevisiae) chromosome IV: entries and gene names