ID HCY2_LIMPO Reviewed; 628 AA. AC P04253; DT 20-MAR-1987, integrated into UniProtKB/Swiss-Prot. DT 01-JUL-1989, sequence version 2. DT 10-JUN-2026, entry version 119. DE RecName: Full=Hemocyanin II; OS Limulus polyphemus (Atlantic horseshoe crab). OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Merostomata; OC Xiphosura; Limulidae; Limulus. OX NCBI_TaxID=6850; RN [1] RP PROTEIN SEQUENCE. RX PubMed=3525550; DOI=10.1016/s0021-9258(18)67416-2; RA Nakashima H., Behrens P.Q., Moore M.D., Yokota E., Riggs A.F.; RT "Structure of hemocyanin II from the horseshoe crab, Limulus polyphemus. RT Sequences of the overlapping peptides, ordering the CNBr fragments, and the RT complete amino acid sequence."; RL J. Biol. Chem. 261:10526-10533(1986). RN [2] RP PROTEIN SEQUENCE OF 1-203. RX PubMed=6715319; DOI=10.1016/s0021-9258(17)42909-7; RA Yokota E., Riggs A.F.; RT "The structure of the hemocyanin from the horseshoe crab, Limulus RT polyphemus. The amino acid sequence of the largest cyanogen bromide RT fragment."; RL J. Biol. Chem. 259:4739-4749(1984). RN [3] RP X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS). RX PubMed=1866430; DOI=10.1002/prot.340090403; RA Magnus K.A., Lattman E.E., Volbeda A., Hol W.G.J.; RT "Hexamers of subunit II from Limulus hemocyanin (a 48-mer) have the same RT quaternary structure as whole Panulirus hemocyanin molecules."; RL Proteins 9:240-247(1991). RN [4] RP X-RAY CRYSTALLOGRAPHY (2.18 ANGSTROMS). RX PubMed=8518732; DOI=10.1002/pro.5560020411; RA Hazes B., Magnus K.A., Bonaventura C., Bonaventura J., Dauter Z., RA Kalk K.H., Hol W.G.J.; RT "Crystal structure of deoxygenated Limulus polyphemus subunit II hemocyanin RT at 2.18-A resolution: clues for a mechanism for allosteric regulation."; RL Protein Sci. 2:597-619(1993). CC -!- FUNCTION: Hemocyanins are copper-containing oxygen carriers occurring CC freely dissolved in the hemolymph of many mollusks and arthropods. CC -!- SUBUNIT: Hexamer or a multiple thereof. CC -!- SUBCELLULAR LOCATION: Secreted, extracellular space. CC -!- TISSUE SPECIFICITY: Hemolymph. CC -!- SIMILARITY: Belongs to the tyrosinase family. Hemocyanin subfamily. CC {ECO:0000305}. 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 PIR; A26713; BHHC2A. DR PDB; 1LL1; X-ray; 2.55 A; A=1-628. DR PDB; 1LLA; X-ray; 2.18 A; A=1-628. DR PDB; 1NOL; X-ray; 2.40 A; A=1-628. DR PDB; 1OXY; X-ray; 2.40 A; A=1-628. DR AlphaFoldDB; P04253; -. DR SMR; P04253; -. DR EnsemblMetazoa; NM_001314143.1; NP_001301072.1; LOC106468801. DR OrthoDB; 8119704at2759; -. DR EvolutionaryTrace; P04253; -. DR Proteomes; UP000694941; Unplaced. DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell. DR GO; GO:0031404; F:chloride ion binding; IDA:UniProtKB. DR GO; GO:0005507; F:copper ion binding; IDA:UniProtKB. DR GO; GO:0016491; F:oxidoreductase activity; IEA:InterPro. DR GO; GO:0005344; F:oxygen carrier activity; NAS:UniProtKB. DR GO; GO:0015671; P:oxygen transport; NAS:UniProtKB. DR FunFam; 1.10.1280.10:FF:000004; Hemocyanin subunit 2; 1. DR FunFam; 2.60.40.1520:FF:000001; Hemocyanin subunit 2; 1. DR FunFam; 1.20.1370.10:FF:000002; Hemocyanin subunit B; 1. DR Gene3D; 1.10.1280.10; Di-copper center containing domain from catechol oxidase; 1. DR Gene3D; 2.60.40.1520; Hemocyanin, C-terminal domain; 1. DR Gene3D; 1.20.1370.10; Hemocyanin, N-terminal domain; 1. DR InterPro; IPR008922; Di-copper_centre_dom_sf. DR InterPro; IPR013788; Hemocyanin/hexamerin. DR InterPro; IPR000896; Hemocyanin/hexamerin_mid_dom. DR InterPro; IPR005203; Hemocyanin_C. DR InterPro; IPR037020; Hemocyanin_C_sf. DR InterPro; IPR005204; Hemocyanin_N. DR InterPro; IPR036697; Hemocyanin_N_sf. DR InterPro; IPR014756; Ig_E-set. DR InterPro; IPR002227; Tyrosinase_Cu-bd. DR PANTHER; PTHR11511:SF5; FAT-BODY PROTEIN 1-RELATED; 1. DR PANTHER; PTHR11511; LARVAL STORAGE PROTEIN/PHENOLOXIDASE; 1. DR Pfam; PF03723; Hemocyanin_C; 1. DR Pfam; PF00372; Hemocyanin_M; 1. DR Pfam; PF03722; Hemocyanin_N; 1. DR PRINTS; PR00187; HAEMOCYANIN. DR SUPFAM; SSF48056; Di-copper centre-containing domain; 1. DR SUPFAM; SSF81296; E set domains; 1. DR SUPFAM; SSF48050; Hemocyanin, N-terminal domain; 1. DR PROSITE; PS00209; HEMOCYANIN_1; 1. DR PROSITE; PS00210; HEMOCYANIN_2; 1. DR PROSITE; PS00498; TYROSINASE_2; 1. DR PDBsum; 1LL1; -. DR PDBsum; 1LLA; -. DR PDBsum; 1NOL; -. DR PDBsum; 1OXY; -. PE 1: Evidence at protein level; KW 3D-structure; Copper; Direct protein sequencing; Disulfide bond; KW Glycoprotein; Metal-binding; Oxygen transport; Reference proteome; KW Secreted; Transport. FT CHAIN 1..628 FT /note="Hemocyanin II" FT /id="PRO_0000204281" FT BINDING 173 FT /ligand="Cu cation" FT /ligand_id="ChEBI:CHEBI:23378" FT /ligand_label="1" FT /evidence="ECO:0000269|PubMed:8518732" FT BINDING 177 FT /ligand="Cu cation" FT /ligand_id="ChEBI:CHEBI:23378" FT /ligand_label="1" FT /evidence="ECO:0000269|PubMed:8518732" FT BINDING 204 FT /ligand="Cu cation" FT /ligand_id="ChEBI:CHEBI:23378" FT /ligand_label="1" FT /evidence="ECO:0000269|PubMed:8518732" FT BINDING 324 FT /ligand="Cu cation" FT /ligand_id="ChEBI:CHEBI:23378" FT /ligand_label="2" FT /evidence="ECO:0000269|PubMed:8518732" FT BINDING 328 FT /ligand="Cu cation" FT /ligand_id="ChEBI:CHEBI:23378" FT /ligand_label="2" FT /evidence="ECO:0000269|PubMed:8518732" FT BINDING 364 FT /ligand="Cu cation" FT /ligand_id="ChEBI:CHEBI:23378" FT /ligand_label="2" FT /evidence="ECO:0000269|PubMed:8518732" FT MOD_RES 1 FT /note="Blocked amino end (Thr); partial" FT /evidence="ECO:0000269|PubMed:3525550" FT CARBOHYD 449 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255" FT DISULFID 534..576 FT DISULFID 536..583 FT HELIX 3..13 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 16..18 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 33..36 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 45..47 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 48..50 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 51..65 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 67..69 FT /evidence="ECO:0007829|PDB:1OXY" FT HELIX 70..80 FT /evidence="ECO:0007829|PDB:1LLA" FT TURN 81..83 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 86..99 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 101..103 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 106..110 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 111..114 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 116..118 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 122..130 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 143..146 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 156..160 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 161..164 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 167..179 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 186..189 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 196..217 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 221..225 FT /evidence="ECO:0007829|PDB:1LLA" FT TURN 243..246 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 249..251 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 266..282 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 284..286 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 292..294 FT /evidence="ECO:0007829|PDB:1LLA" FT TURN 297..299 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 300..309 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 317..320 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 323..332 FT /evidence="ECO:0007829|PDB:1LLA" FT TURN 333..335 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 343..345 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 347..349 FT /evidence="ECO:0007829|PDB:1LLA" FT TURN 351..353 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 354..356 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 358..375 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 379..382 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 383..386 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 391..402 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 405..416 FT /evidence="ECO:0007829|PDB:1LLA" FT TURN 418..420 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 429..438 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 442..449 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 451..453 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 455..467 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 476..482 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 484..493 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 495..503 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 504..506 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 510..512 FT /evidence="ECO:0007829|PDB:1NOL" FT HELIX 514..516 FT /evidence="ECO:0007829|PDB:1NOL" FT HELIX 517..521 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 537..539 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 540..542 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 548..550 FT /evidence="ECO:0007829|PDB:1OXY" FT STRAND 552..562 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 563..566 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 580..583 FT /evidence="ECO:0007829|PDB:1LLA" FT TURN 596..599 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 600..602 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 606..608 FT /evidence="ECO:0007829|PDB:1LLA" FT HELIX 609..611 FT /evidence="ECO:0007829|PDB:1LLA" FT STRAND 617..626 FT /evidence="ECO:0007829|PDB:1LLA" SQ SEQUENCE 628 AA; 72629 MW; 6B8B4C6D8B1225BE CRC64; TLHDKQIRVC HLFEQLSSAT VIGDGDKHKH SDRLKNVGKL QPGAIFSCFH PDHLEEARHL YEVFWEAGDF NDFIEIAKEA RTFVNEGLFA FAAEVAVLHR DDCKGLYVPP VQEIFPDKFI PSAAINEAFK KAHVRPEFDE SPILVDVQDT GNILDPEYRL AYYREDVGIN AHHWHWHLVY PSTWNPKYFG KKKDRKGELF YYMHQQMCAR YDCERLSNGM HRMLPFNNFD EPLAGYAPHL THVASGKYYS PRPDGLKLRD LGDIEISEMV RMRERILDSI HLGYVISEDG SHKTLDELHG TDILGALVES SYESVNHEYY GNLHNWGHVT MARIHDPDGR FHEEPGVMSD TSTSLRDPIF YNWHRFIDNI FHEYKNTLKP YDHDVLNFPD IQVQDVTLHA RVDNVVHFTM REQELELKHG INPGNARSIK ARYYHLDHEP FSYAVNVQNN SASDKHATVR IFLAPKYDEL GNEIKADELR RTAIELDKFK TDLHPGKNTV VRHSLDSSVT LSHQPTFEDL LHGVGLNEHK SEYCSCGWPS HLLVPKGNIK GMEYHLFVML TDWDKDKVDG SESVACVDAV SYCGARDHKY PDKKPMGFPF DRPIHTEHIS DFLTNNMFIK DIKIKFHE //