ID   RBCX_SYNP6              Reviewed;         161 AA.
AC   A0A0H3K9R3;
DT   02-DEC-2020, integrated into UniProtKB/Swiss-Prot.
DT   16-SEP-2015, sequence version 1.
DT   03-AUG-2022, entry version 24.
DE   RecName: Full=RuBisCO chaperone RbcX {ECO:0000255|HAMAP-Rule:MF_00855, ECO:0000303|PubMed:20075914};
GN   Name=rbcX {ECO:0000255|HAMAP-Rule:MF_00855, ECO:0000303|PubMed:17211581};
GN   OrderedLocusNames=syc2521_d;
OS   Synechococcus sp. (strain ATCC 27144 / PCC 6301 / SAUG 1402/1) (Anacystis
OS   nidulans).
OC   Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Synechococcus.
OX   NCBI_TaxID=269084;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 27144 / PCC 6301 / SAUG 1402/1;
RX   PubMed=17211581; DOI=10.1007/s11120-006-9122-4;
RA   Sugita C., Ogata K., Shikata M., Jikuya H., Takano J., Furumichi M.,
RA   Kanehisa M., Omata T., Sugiura M., Sugita M.;
RT   "Complete nucleotide sequence of the freshwater unicellular cyanobacterium
RT   Synechococcus elongatus PCC 6301 chromosome: gene content and
RT   organization.";
RL   Photosyn. Res. 93:55-67(2007).
RN   [2]
RP   FUNCTION, AND SUBUNIT.
RC   STRAIN=ATCC 27144 / PCC 6301 / SAUG 1402/1;
RX   PubMed=20075914; DOI=10.1038/nature08651;
RA   Liu C., Young A.L., Starling-Windhof A., Bracher A., Saschenbrecker S.,
RA   Rao B.V., Rao K.V., Berninghausen O., Mielke T., Hartl F.U., Beckmann R.,
RA   Hayer-Hartl M.;
RT   "Coupled chaperone action in folding and assembly of hexadecameric
RT   Rubisco.";
RL   Nature 463:197-202(2010).
RN   [3]
RP   SUBUNIT.
RC   STRAIN=ATCC 27144 / PCC 6301 / SAUG 1402/1;
RX   PubMed=21765418; DOI=10.1038/nsmb.2090;
RA   Bracher A., Starling-Windhof A., Hartl F.U., Hayer-Hartl M.;
RT   "Crystal structure of a chaperone-bound assembly intermediate of form I
RT   Rubisco.";
RL   Nat. Struct. Mol. Biol. 18:875-880(2011).
CC   -!- FUNCTION: An RbcL-specific chaperone. The central cleft of the RbcX
CC       homodimer (RbcX2) binds the C-terminus of an RbcL monomer, stabilizing
CC       the C-terminus and probably preventing its reassociation with
CC       chaperonin GroEL-ES. At the same time the peripheral region of RbcX2
CC       binds a second RbcL monomer, bridging the RbcL homodimers in the
CC       correct orientation. The RbcX2(2)-bound RbcL dimers then assemble into
CC       the RbcL8 core (RbcL8-(RbcX2)8). RbcS binding triggers the release of
CC       RbcX2. {ECO:0000255|HAMAP-Rule:MF_00855, ECO:0000305|PubMed:20075914}.
CC   -!- SUBUNIT: Homodimer (Probable). Interacts with the exposed C-terminal
CC       peptide of endogenous RbcL ('Lys-460-Asp-470') via its central cleft,
CC       as well as C-terminal peptides from other cyanobacterial RbcL
CC       (PubMed:20075914, PubMed:21765418). Contacts a second RbcL monomer via
CC       its peripheral polar surface (By similarity).
CC       {ECO:0000250|UniProtKB:Q44212, ECO:0000269|PubMed:20075914,
CC       ECO:0000269|PubMed:21765418, ECO:0000305|PubMed:20075914,
CC       ECO:0000305|PubMed:21765418}.
CC   -!- INTERACTION:
CC       A0A0H3K9R3; P00880: cbbL; NbExp=3; IntAct=EBI-15936812, EBI-9023246;
CC   -!- SUBCELLULAR LOCATION: Carboxysome {ECO:0000255|HAMAP-Rule:MF_00855}.
CC       Cytoplasm {ECO:0000255|HAMAP-Rule:MF_00855}. Note=Most protein is
CC       cytoplasmic, but some is in the carboxysome. This cyanobacterium makes
CC       beta-type carboxysomes (Probable). {ECO:0000255|HAMAP-Rule:MF_00855,
CC       ECO:0000305}.
CC   -!- DOMAIN: The homodimer has 2 functional domains, a central cleft
CC       essential for production of soluble RbcL in which the RbcL peptide
CC       binds, and a polar surface which plays a role in correct RbcL subunit
CC       arrangement. {ECO:0000255|HAMAP-Rule:MF_00855}.
CC   -!- SIMILARITY: Belongs to the RbcX family. {ECO:0000255|HAMAP-
CC       Rule:MF_00855}.
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DR   EMBL; AP008231; BAD80711.1; -; Genomic_DNA.
DR   AlphaFoldDB; A0A0H3K9R3; -.
DR   SMR; A0A0H3K9R3; -.
DR   IntAct; A0A0H3K9R3; 1.
DR   STRING; 269084.syc2521_d; -.
DR   EnsemblBacteria; BAD80711; BAD80711; syc2521_d.
DR   KEGG; syc:syc2521_d; -.
DR   eggNOG; ENOG50315SX; Bacteria.
DR   OMA; DYLPEMV; -.
DR   Proteomes; UP000001175; Chromosome.
DR   GO; GO:0031470; C:carboxysome; IEA:UniProtKB-SubCell.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0044183; F:protein folding chaperone; IEA:InterPro.
DR   GO; GO:0015977; P:carbon fixation; IEA:UniProtKB-KW.
DR   GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-KW.
DR   GO; GO:0110102; P:ribulose bisphosphate carboxylase complex assembly; IPI:UniProtKB.
DR   Gene3D; 1.10.1200.210; -; 1.
DR   HAMAP; MF_00855; RbcX; 1.
DR   InterPro; IPR038052; Chaperonin_RbcX_sf.
DR   InterPro; IPR003435; Chaperonin_RcbX.
DR   InterPro; IPR046381; RbcX.
DR   PANTHER; PTHR33791; PTHR33791; 1.
DR   Pfam; PF02341; RbcX; 1.
DR   SUPFAM; SSF158615; SSF158615; 1.
PE   1: Evidence at protein level;
KW   Bacterial microcompartment; Carbon dioxide fixation; Carboxysome;
KW   Chaperone; Cytoplasm; Photosynthesis.
FT   CHAIN           1..161
FT                   /note="RuBisCO chaperone RbcX"
FT                   /id="PRO_0000451302"
FT   REGION          1..20
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          130..161
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        141..161
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   161 AA;  17992 MW;  7963D430A935C0EB CRC64;
     MQFMGTASRM ASTQRAKPME MPRISRDTAR MLVNYLTYQA VCVIRDQLAE TNPAGAYRLQ
     VFSAEFSFQD GEAYLAALLN HDRELGLRVM TVREHLAEHI LDYLPEMTIA QIQEANINHR
     RALLERLTGL GAEPSLPETE VSDRPSDSAT PDDASNASHA D