ID RBCX_ANASC Reviewed; 135 AA. AC Q44212; DT 02-DEC-2020, integrated into UniProtKB/Swiss-Prot. DT 01-NOV-1996, sequence version 1. DT 24-JAN-2024, entry version 69. DE RecName: Full=RuBisCO chaperone RbcX {ECO:0000255|HAMAP-Rule:MF_00855, ECO:0000303|PubMed:9171433}; GN Name=rbcX {ECO:0000255|HAMAP-Rule:MF_00855, GN ECO:0000303|PubMed:7961423}; OS Anabaena sp. (strain CA / ATCC 33047). OC Bacteria; Cyanobacteriota; Cyanophyceae; Nostocales; Nostocaceae; Anabaena. OX NCBI_TaxID=52271; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], INDUCTION BY LIGHT, AND OPERON RP STRUCTURE. RC STRAIN=CA / ATCC 33047; RX PubMed=7961423; DOI=10.1128/jb.176.21.6697-6706.1994; RA Li L.A., Tabita F.R.; RT "Transcription control of ribulose bisphosphate carboxylase/oxygenase RT activase and adjacent genes in Anabaena species."; RL J. Bacteriol. 176:6697-6706(1994). RN [2] RP FUNCTION UPON EXPRESSION IN E.COLI. RC STRAIN=CA / ATCC 33047; RX PubMed=9171433; DOI=10.1128/jb.179.11.3793-3796.1997; RA Li L.A., Tabita F.R.; RT "Maximum activity of recombinant ribulose 1,5-bisphosphate RT carboxylase/oxygenase of Anabaena sp. strain CA requires the product of the RT rbcX gene."; RL J. Bacteriol. 179:3793-3796(1997). RN [3] {ECO:0007744|PDB:2PEO} RP X-RAY CRYSTALLOGRAPHY (2.50 ANGSTROMS), FUNCTION, SUBUNIT, AND DOMAIN. RC STRAIN=CA / ATCC 33047; RX PubMed=17574029; DOI=10.1016/j.cell.2007.04.025; RA Saschenbrecker S., Bracher A., Rao K.V., Rao B.V., Hartl F.U., RA Hayer-Hartl M.; RT "Structure and function of RbcX, an assembly chaperone for hexadecameric RT Rubisco."; RL Cell 129:1189-1200(2007). RN [4] {ECO:0007744|PDB:2WVW, ECO:0007744|PDB:3HYB} RP X-RAY CRYSTALLOGRAPHY (2.30 ANGSTROMS), STRUCTURE BY ELECTRON MICROSCOPY RP (9.00 ANGSTROMS) IN COMPLEX WITH SYNECHOCOCCUS RBCL, FUNCTION, SUBUNIT, RP DOMAIN, AND MUTAGENESIS OF 17-TYR--TYR-20 AND GLN-29. RC STRAIN=CA / ATCC 33047; 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 [5] {ECO:0007744|PDB:3RG6} RP X-RAY CRYSTALLOGRAPHY (3.20 ANGSTROMS) IN COMPLEX WITH SYNECHOCOCCUS RBCL, RP FUNCTION, AND SUBUNIT. RC STRAIN=CA / ATCC 33047; 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 (PubMed:20075914, PubMed:21765418). {ECO:0000255|HAMAP- CC Rule:MF_00855, ECO:0000269|PubMed:20075914, CC ECO:0000269|PubMed:21765418}. CC -!- FUNCTION: Required for optimal reconstitution of RuBisCO upon CC expression of rbcL-rbcS subunits in E.coli (PubMed:9171433). CC {ECO:0000269|PubMed:9171433}. CC -!- SUBUNIT: Homodimer. Interacts with the exposed C-terminal peptide of CC RbcL ('Glu-459-Asp-468'); binds 1 RbcL peptide per homodimer CC (PubMed:17574029, PubMed:20075914, PubMed:21765418). Contacts a second CC RbcL monomer via its peripheral polar surface (PubMed:21765418). A CC slightly longer RbcL peptide binds to RbcX2 with a higher affinity CC (PubMed:17574029). {ECO:0000269|PubMed:17574029, CC ECO:0000269|PubMed:20075914, ECO:0000269|PubMed:21765418}. CC -!- INTERACTION: CC Q44212; P00880: cbbL; Xeno; NbExp=3; IntAct=EBI-9023244, 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. {ECO:0000255|HAMAP- CC Rule:MF_00855}. CC -!- INDUCTION: Transcribed in light but much less in the dark in both CC normal air and 1% CO(2); the nitrogen source has no effect on CC transcription. Constitutively expressed when grown on fructose. Part of CC the rbcL-rbcX-rbcS operon. {ECO:0000269|PubMed:7961423}. 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 ECO:0000269|PubMed:20075914, ECO:0000305|PubMed:17574029}. CC -!- SIMILARITY: Belongs to the RbcX family. {ECO:0000255|HAMAP- CC Rule:MF_00855}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; U05590; AAA63603.1; -; Genomic_DNA. DR RefSeq; WP_066380855.1; NZ_LUHI01000044.1. DR PDB; 2PEO; X-ray; 2.50 A; A/B=1-135. DR PDB; 2WVW; EM; 9.00 A; I/J/K/L/M/N/O/P/Q/R/S/T/U/V/W/X=1-135. DR PDB; 3HYB; X-ray; 2.30 A; A/B=1-135. DR PDB; 3RG6; X-ray; 3.20 A; C/D/E/F=1-135. DR PDBsum; 2PEO; -. DR PDBsum; 2WVW; -. DR PDBsum; 3HYB; -. DR PDBsum; 3RG6; -. DR AlphaFoldDB; Q44212; -. DR EMDB; EMD-1654; -. DR SMR; Q44212; -. DR DIP; DIP-59100N; -. DR IntAct; Q44212; 1. DR EvolutionaryTrace; Q44212; -. 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:0042803; F:protein homodimerization activity; IDA:UniProtKB. DR GO; GO:0015977; P:carbon fixation; IEA:UniProtKB-UniRule. DR GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-KW. DR GO; GO:0110102; P:ribulose bisphosphate carboxylase complex assembly; IDA:UniProtKB. DR Gene3D; 1.10.1200.210; Chaperonin-like RbcX; 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; CHAPERONIN-LIKE RBCX PROTEIN 1, CHLOROPLASTIC; 1. DR PANTHER; PTHR33791:SF12; CHAPERONIN-LIKE RBCX PROTEIN 1, CHLOROPLASTIC; 1. DR Pfam; PF02341; RbcX; 1. DR SUPFAM; SSF158615; RbcX-like; 1. PE 1: Evidence at protein level; KW 3D-structure; Bacterial microcompartment; Carbon dioxide fixation; KW Carboxysome; Chaperone; Cytoplasm; Photosynthesis. FT CHAIN 1..135 FT /note="RuBisCO chaperone RbcX" FT /id="PRO_0000451299" FT REGION 103..135 FT /note="Disordered" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT COMPBIAS 109..135 FT /note="Polar residues" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT MUTAGEN 17..20 FT /note="YLTY->ALTA: No longer prevents RbcL-GroEL FT association." FT /evidence="ECO:0000269|PubMed:20075914" FT MUTAGEN 29 FT /note="Q->A: No longer prevents RbcL-GroEL association." FT /evidence="ECO:0000269|PubMed:20075914" FT HELIX 3..33 FT /evidence="ECO:0007829|PDB:3HYB" FT HELIX 35..45 FT /evidence="ECO:0007829|PDB:3HYB" FT HELIX 52..62 FT /evidence="ECO:0007829|PDB:3HYB" FT HELIX 64..81 FT /evidence="ECO:0007829|PDB:3HYB" FT HELIX 82..84 FT /evidence="ECO:0007829|PDB:3HYB" FT HELIX 85..103 FT /evidence="ECO:0007829|PDB:3HYB" SQ SEQUENCE 135 AA; 15507 MW; 5CE932C99D632FEC CRC64; MNLKQIAKDT AKTLQSYLTY QALRTVLAQL GETNPPLALW LHNFSAGKVQ DGEKYIEELF LEKPDLALRI MTVREHIAEE IAEFLPEMVV TGIQQANMEK RRQHLERMTQ VSLSHPSPES EQQQFSDPDW DNLAS //