CFB_TACTR
ID CFB_TACTR Reviewed; 400 AA.
AC Q27081;
DT 18-MAY-2010, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1996, sequence version 1.
DT 25-MAY-2022, entry version 86.
DE RecName: Full=Clotting factor B {ECO:0000303|PubMed:3519594};
DE EC=3.4.21.85;
DE AltName: Full=Coagulation factor B {ECO:0000303|PubMed:8407978, ECO:0000312|EMBL:BAA03528.1};
DE Contains:
DE RecName: Full=Clotting factor B light chain {ECO:0000303|PubMed:3519594, ECO:0000303|PubMed:8407978};
DE Contains:
DE RecName: Full=Clotting factor B heavy chain {ECO:0000303|PubMed:3519594, ECO:0000303|PubMed:8407978};
DE Flags: Precursor;
OS Tachypleus tridentatus (Japanese horseshoe crab).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Merostomata;
OC Xiphosura; Limulidae; Tachypleus.
OX NCBI_TaxID=6853;
RN [1] {ECO:0000305, ECO:0000312|EMBL:BAA03528.1}
RP NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 24-44; 49-53; 55-61; 63-68;
RP 127-136; 148-150; 152-158; 162-185; 187-247; 274-280; 307-313; 322-337;
RP 368-373; 376-378; 380-385 AND 391-400, AND PROTEOLYTIC PROCESSING.
RC TISSUE=Hemocyte {ECO:0000269|PubMed:8407978};
RX PubMed=8407978; DOI=10.1016/s0021-9258(19)36934-0;
RA Muta T., Oda T., Iwanaga S.;
RT "Horseshoe crab coagulation factor B. A unique serine protease zymogen
RT activated by cleavage of an Ile-Ile bond.";
RL J. Biol. Chem. 268:21384-21388(1993).
RN [2] {ECO:0000305}
RP FUNCTION, ACTIVITY REGULATION, BIOPHYSICOCHEMICAL PROPERTIES, AND SUBUNIT.
RX PubMed=3519594; DOI=10.1093/oxfordjournals.jbchem.a135545;
RA Nakamura T., Horiuchi T., Morita T., Iwanaga S.;
RT "Purification and properties of intracellular clotting factor, factor B,
RT from horseshoe crab (Tachypleus tridentatus) hemocytes.";
RL J. Biochem. 99:847-857(1986).
RN [3] {ECO:0000305}
RP FUNCTION, AND CATALYTIC ACTIVITY.
RX PubMed=2266134; DOI=10.1016/s0021-9258(18)45722-5;
RA Muta T., Hashimoto R., Miyata T., Nishimura H., Toh Y., Iwanaga S.;
RT "Proclotting enzyme from horseshoe crab hemocytes. cDNA cloning, disulfide
RT locations, and subcellular localization.";
RL J. Biol. Chem. 265:22426-22433(1990).
CC -!- FUNCTION: This enzyme is closely associated with an endotoxin-sensitive
CC hemolymph coagulation system which may play important roles in both
CC hemostasis and host defense mechanisms. Its active form catalyzes the
CC activation of proclotting enzyme. Does not activate the mammalian
CC coagulation factors factor IX, factor X, prothrombin, plasminogen,
CC protein C or prekallikrein. Does not hydrolyze fibrinogen. Does not
CC catalyze the activation of factor C or coagulogen.
CC {ECO:0000269|PubMed:2266134, ECO:0000269|PubMed:3519594}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=Selective cleavage of 98-Arg-|-Ile-99 bond in Limulus
CC proclotting enzyme to form active clotting enzyme.; EC=3.4.21.85;
CC Evidence={ECO:0000269|PubMed:2266134};
CC -!- ACTIVITY REGULATION: Strongly inhibited by alpha2-plasmin inhibitor and
CC DFP. Partially inhibited by benzamidine, leupeptin and PCMB.
CC {ECO:0000269|PubMed:3519594}.
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC Vmax=0.9 umol/min/mg enzyme toward Boc-Val-Pro-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=0.1 umol/min/mg enzyme toward Boc-Ile-Glu-Gly-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=0.2 umol/min/mg enzyme toward Boc-Leu-Ser-Thr-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=0.1 umol/min/mg enzyme toward Boc-Leu-Gly-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=1.1 umol/min/mg enzyme toward Bz-Thr-Ser-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=0.7 umol/min/mg enzyme toward Bz-Ser-Ser-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=1.3 umol/min/mg enzyme toward Bz-Ser-Thr-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=1.9 umol/min/mg enzyme toward Bz-Thr-Thr-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=1.1 umol/min/mg enzyme toward Boc-Leu-Thr-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=2.1 umol/min/mg enzyme toward Boc-Met-Thr-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=1.2 umol/min/mg enzyme toward Boc-Gln-Arg-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC Vmax=0.6 umol/min/mg enzyme toward Boc-Asp-Pro-Arg-MCA
CC {ECO:0000269|PubMed:3519594};
CC -!- SUBUNIT: Upon activation by factor C, it is converted to a two-chain
CC active form composed of a light and a heavy chain linked by a disulfide
CC bond. {ECO:0000269|PubMed:3519594}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305}. Note=Secreted in
CC hemolymph. {ECO:0000305}.
CC -!- DOMAIN: The clip domain consists of 35-55 residues which are 'knitted'
CC together usually by 3 conserved disulfide bonds forming a clip-like
CC compact structure. {ECO:0000255|PROSITE-ProRule:PRU01236}.
CC -!- SIMILARITY: Belongs to the peptidase S1 family. CLIP subfamily.
CC {ECO:0000255|PROSITE-ProRule:PRU01236}.
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DR EMBL; D14701; BAA03528.1; -; mRNA.
DR PIR; A48050; A48050.
DR AlphaFoldDB; Q27081; -.
DR SMR; Q27081; -.
DR MEROPS; S01.220; -.
DR KEGG; ag:BAA03528; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0004175; F:endopeptidase activity; IDA:UniProtKB.
DR GO; GO:0004252; F:serine-type endopeptidase activity; IEA:InterPro.
DR GO; GO:0042381; P:hemolymph coagulation; IDA:UniProtKB.
DR GO; GO:0016485; P:protein processing; IDA:UniProtKB.
DR CDD; cd00190; Tryp_SPc; 1.
DR Gene3D; 2.40.10.10; -; 1.
DR InterPro; IPR022700; CLIP.
DR InterPro; IPR009003; Peptidase_S1_PA.
DR InterPro; IPR043504; Peptidase_S1_PA_chymotrypsin.
DR InterPro; IPR001314; Peptidase_S1A.
DR InterPro; IPR001254; Trypsin_dom.
DR InterPro; IPR033116; TRYPSIN_SER.
DR Pfam; PF00089; Trypsin; 1.
DR PRINTS; PR00722; CHYMOTRYPSIN.
DR SMART; SM00680; CLIP; 1.
DR SMART; SM00020; Tryp_SPc; 1.
DR SUPFAM; SSF50494; SSF50494; 1.
DR PROSITE; PS51888; CLIP; 1.
DR PROSITE; PS50240; TRYPSIN_DOM; 1.
DR PROSITE; PS00135; TRYPSIN_SER; 1.
PE 1: Evidence at protein level;
KW Direct protein sequencing; Disulfide bond; Glycoprotein;
KW Hemolymph clotting; Hydrolase; Protease; Secreted; Serine protease; Signal;
KW Zymogen.
FT SIGNAL 1..23
FT /evidence="ECO:0000269|PubMed:8407978"
FT CHAIN 24..103
FT /note="Clotting factor B light chain"
FT /evidence="ECO:0000269|PubMed:8407978"
FT /id="PRO_0000394311"
FT PROPEP 104..124
FT /note="Activation peptide"
FT /evidence="ECO:0000269|PubMed:8407978"
FT /id="PRO_0000394312"
FT CHAIN 125..400
FT /note="Clotting factor B heavy chain"
FT /evidence="ECO:0000269|PubMed:8407978"
FT /id="PRO_0000394313"
FT DOMAIN 36..80
FT /note="Clip"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01236"
FT DOMAIN 148..392
FT /note="Peptidase S1"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT ACT_SITE 192
FT /note="Charge relay system"
FT /evidence="ECO:0000250|UniProtKB:P26262"
FT ACT_SITE 240
FT /note="Charge relay system"
FT /evidence="ECO:0000250|UniProtKB:P26262"
FT ACT_SITE 344
FT /note="Charge relay system"
FT /evidence="ECO:0000250|UniProtKB:P26262"
FT CARBOHYD 140
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 251
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 352
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT DISULFID 37..79
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01236"
FT DISULFID 47..68
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01236"
FT DISULFID 53..80
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01236"
FT DISULFID 307..329
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT DISULFID 340..368
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
SQ SEQUENCE 400 AA; 43049 MW; E71D4D808543C85B CRC64;
MTWICVITLF ALASATLGNK VSRVGVLFPK TRNDNECTAR GGLKGSCKSL IDCPSVLATL
KDSFPVVCSW NGRFQPIVCC PDAIAPPPVT TTAVTVISTK EPKLPRLHIS GCGKRKVKID
ITTVGRSGSP ILPPISTPQN STGGRGIIAG GVEAKIGAWP WMAAVFVKNF GIGRFHCAGS
IISNKYILSA AHAFLIGGRK LTPTRLAVRV GGHYIKRGQE YPVKDVIIHP HYVEKENYND
IAIIELKEEL NFTDLVNPIC LPDPETVTDP LKDRIVTAAG WGDLDFSGPR SQVLREVSIP
VVPVDKCDQA YEKLNTPSLK NGITNNFLCA GLEEGGKDAC QGDSGGPLML VNNTRWIVVG
VVSFGHKCAE EGYPGVYSRV ASYLDWIAKV TNSLDHAVTN
