SSB1_KLUMA
ID SSB1_KLUMA Reviewed; 613 AA.
AC P41770; Q707X6;
DT 01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT 23-JAN-2007, sequence version 2.
DT 03-AUG-2022, entry version 82.
DE RecName: Full=Ribosome-associated molecular chaperone SSB1;
DE EC=3.6.4.10;
DE AltName: Full=Heat shock protein SSB1;
DE AltName: Full=Hsp70 chaperone Ssb;
GN Name=SSB1;
OS Kluyveromyces marxianus (Yeast) (Candida kefyr).
OC Eukaryota; Fungi; Dikarya; Ascomycota; Saccharomycotina; Saccharomycetes;
OC Saccharomycetales; Saccharomycetaceae; Kluyveromyces.
OX NCBI_TaxID=4911;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=ATCC 12424 / NRRL Y-610;
RA Iborra F.;
RL Submitted (MAY-1991) to the EMBL/GenBank/DDBJ databases.
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=ATCC 200963 / CBS 712 / NBRC 10005 / NRRL Y-8281 / HA 63;
RX PubMed=14745027; DOI=10.1073/pnas.0304170101;
RA Butler G., Kenny C., Fagan A., Kurischko C., Gaillardin C., Wolfe K.H.;
RT "Evolution of the MAT locus and its Ho endonuclease in yeast species.";
RL Proc. Natl. Acad. Sci. U.S.A. 101:1632-1637(2004).
CC -!- FUNCTION: Ribosome-bound, Hsp70-type chaperone that assists in the
CC cotranslational folding of newly synthesized proteins in the cytosol.
CC Stimulates folding by interacting with nascent chains, binding to
CC short, largely hydrophobic sequences exposed by unfolded proteins,
CC thereby stabilizing longer, more slowly translated, and aggregation-
CC prone nascent polypeptides and domains that cannot fold stably until
CC fully synthesized. The Hsp70-protein substrate interaction depends on
CC ATP-binding and on allosteric regulation between the NBD and the SBD.
CC The ATP-bound state is characterized by a fast exchange rate of
CC substrate (low affinity state), while in the ADP-bound state exchange
CC is much slower (high affinity state). During the Hsp70 cycle, the
CC chaperone switches between the ATP-bound state (open conformation) and
CC the ADP-bound state (closed conformation) by major conformational
CC rearrangements involving mainly the lid domain. Ssb cooperates with a
CC specific Hsp40/Hsp70 co-chaperone termed the ribosome-associated
CC complex (RAC), which stimulates the ATPase activity of the ribosome-
CC associated pool of Ssbs and switches it to the high affinity substrate
CC binding state. Hsp110 chaperone SSE1 and FES1 act as nucleotide
CC exchange factors that cause substrate release.
CC {ECO:0000250|UniProtKB:P11484}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=ATP + H2O = ADP + H(+) + phosphate; Xref=Rhea:RHEA:13065,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:30616,
CC ChEBI:CHEBI:43474, ChEBI:CHEBI:456216; EC=3.6.4.10;
CC Evidence={ECO:0000250|UniProtKB:P11484};
CC -!- SUBUNIT: Binds to ribosomes. Binds close to the ribosomal tunnel exit
CC via contacts with both ribosomal proteins and rRNA. Directly interacts
CC with nascent polypeptides. This interaction is dependent on the
CC ribosome-associated complex (RAC). Interacts with SSE1. Interacts with
CC FES1. {ECO:0000250|UniProtKB:P11484}.
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P11484}.
CC Note=Associated with translating ribosomes.
CC {ECO:0000250|UniProtKB:P11484}.
CC -!- SIMILARITY: Belongs to the heat shock protein 70 family. Ssb-type Hsp70
CC subfamily. {ECO:0000305}.
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DR EMBL; X59963; CAA42589.1; -; Genomic_DNA.
DR EMBL; AJ617308; CAE84429.1; -; Genomic_DNA.
DR PIR; S30562; S30562.
DR AlphaFoldDB; P41770; -.
DR SMR; P41770; -.
DR PRIDE; P41770; -.
DR GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR GO; GO:0005524; F:ATP binding; IEA:UniProtKB-KW.
DR GO; GO:0016887; F:ATP hydrolysis activity; IEA:RHEA.
DR GO; GO:0140662; F:ATP-dependent protein folding chaperone; IEA:InterPro.
DR GO; GO:0006412; P:translation; IEA:UniProtKB-KW.
DR Gene3D; 1.20.1270.10; -; 1.
DR Gene3D; 2.60.34.10; -; 1.
DR InterPro; IPR043129; ATPase_NBD.
DR InterPro; IPR018181; Heat_shock_70_CS.
DR InterPro; IPR029048; HSP70_C_sf.
DR InterPro; IPR029047; HSP70_peptide-bd_sf.
DR InterPro; IPR013126; Hsp_70_fam.
DR PANTHER; PTHR19375; PTHR19375; 1.
DR Pfam; PF00012; HSP70; 1.
DR SUPFAM; SSF100920; SSF100920; 1.
DR SUPFAM; SSF100934; SSF100934; 1.
DR SUPFAM; SSF53067; SSF53067; 2.
DR PROSITE; PS00297; HSP70_1; 1.
DR PROSITE; PS00329; HSP70_2; 1.
DR PROSITE; PS01036; HSP70_3; 1.
PE 3: Inferred from homology;
KW ATP-binding; Chaperone; Cytoplasm; Hydrolase; Nucleotide-binding;
KW Protein biosynthesis.
FT CHAIN 1..613
FT /note="Ribosome-associated molecular chaperone SSB1"
FT /id="PRO_0000078371"
FT REGION 1..391
FT /note="Nucleotide binding domain (NBD)"
FT /evidence="ECO:0000250|UniProtKB:G0SCU5"
FT REGION 392..402
FT /note="Inter-domain linker"
FT /evidence="ECO:0000250|UniProtKB:G0SCU5"
FT REGION 403..613
FT /note="Substrate binding domain (SBD)"
FT /evidence="ECO:0000250|UniProtKB:G0SCU5"
FT REGION 516..612
FT /note="Lid domain (SBDalpha)"
FT /evidence="ECO:0000250|UniProtKB:G0SCU5"
FT MOTIF 574..582
FT /note="Nuclear export signal"
FT /evidence="ECO:0000250|UniProtKB:P11484"
FT BINDING 16..18
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000250|UniProtKB:G0SCU5"
FT BINDING 73
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000250|UniProtKB:G0SCU5"
FT BINDING 205..207
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000250|UniProtKB:G0SCU5"
FT BINDING 271..278
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000250|UniProtKB:G0SCU5"
FT BINDING 342
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000250|UniProtKB:G0SCU5"
FT CONFLICT 187
FT /note="V -> L (in Ref. 2; CAE84429)"
FT /evidence="ECO:0000305"
FT CONFLICT 191
FT /note="N -> K (in Ref. 2; CAE84429)"
FT /evidence="ECO:0000305"
FT CONFLICT 246
FT /note="T -> A (in Ref. 2; CAE84429)"
FT /evidence="ECO:0000305"
FT CONFLICT 554
FT /note="Q -> E (in Ref. 2; CAE84429)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 613 AA; 66087 MW; 7D3333E769F2CCB6 CRC64;
MAEGVFPGAI GIDLGTTYSC VATYENSVEI IANEQGNRVT PSFVAFTPEE RLIGDAAKNQ
AALNPKNTVF DAKRLIGRRF DEESVQSDMK TWPFKVIDSN GAPLIEVEYL GETKTFSPQE
ISSMVLTKMK EIAEAKIGKK VEKAVVTVPA YFNDAQRQAT KDAGAIAGLN VLRIINEPTA
AAIAYGVGAG NSEKERHVLI FDLGGGTFDV SLLHIAGGVY TVKSTSGNTH LGGQDFDTNL
LEHFKTEFKK KTGADISGDA RALRRLRTAA ERAKRTLSSV AQTTVEVDSL FDGEDFEATI
TRARFEDINA ALFKSTLEPV EQVLKDAKIS KSQIDEVVLV GGSTRIPKVQ KLLSDFFDGK
QLEKSINPDE AVAYGAAVQG AILTGQSTSD ETKDLLLLDV APLSLGVGMA GDVFGVVVPR
NTTVPTIKRR TFTTVADHQT TVTFPVYQGE RVNCKENTLL GEFDLKGVPP MPAGEPVLEA
IFEVDANGIL KVTAVEKSTG KSANITISNA IGRLSSEEIE QMVNQAEEFK AADEAFAKKH
EARQRLESYI SSVQQTVTDP VLSAKIKRNA KAKVEAALAD AFSTLQIEDA SADDLRKAEV
GLKRAVTKAM STR
