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Conserved domains on  [gi|442760309|gb|JAA72313|]
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Putative salivary kunitz domain protein [Ixodes ricinus]

Protein Classification

Graphical summary

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List of domain hits

Name Accession Description Interval E-value
Kunitz_ixolaris_1 cd22625
Kunitz-type domain 1 (K1) of Ixolaris, and similar proteins; This model includes the first ...
200-249 8.54e-18

Kunitz-type domain 1 (K1) of Ixolaris, and similar proteins; This model includes the first Kunitz-type domain (K1) of ixolaris from the venomous organism Conus striatus. Ixolaris is a potent tick salivary anticoagulant that binds coagulation factor Xa (FXa) and zymogen FX, and forms a quaternary tissue factor (TF)/FVIIa/FX(a)/Ixolaris inhibitory complex. It blocks TF-induced coagulation and PAR2 (proteinase-activated receptor 2) signaling, and prevents thrombosis, tumor growth, and immune activation. Ixolaris consists of 2 Kunitz domains (K1 and K2), both of which recognize the heparin-binding (pro)exosite (HBE) on FX. While K2 is an extraordinarily dynamic domain that encompasses several residues involved in FX binding, K1 domain keeps as a rigid platform supporting the conformational dynamic of the K2 domain, forming a salt bridge with FXa. The structure of this domain is similar to that of Kunitz-type proteinase inhibitors such as BPTI (bovine pancreatic trypsin inhibitor), showing an alpha/beta fold with irregular secondary structure stabilized by three disulfide bonds.


:

Pssm-ID: 438668  Cd Length: 53  Bit Score: 75.76  E-value: 8.54e-18
                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 442760309 200 CTLPIQNITTCEE-PQERYGYNEKTGQCEEFLG--CADGGNSFEEAEKCWKQC 249
Cdd:cd22625    1 CTLPIQEITTCESqPTKRYGYNKKTQQCEEFLGteCGGGGNSFEEAKECWSSC 53
 
Name Accession Description Interval E-value
Kunitz_ixolaris_1 cd22625
Kunitz-type domain 1 (K1) of Ixolaris, and similar proteins; This model includes the first ...
200-249 8.54e-18

Kunitz-type domain 1 (K1) of Ixolaris, and similar proteins; This model includes the first Kunitz-type domain (K1) of ixolaris from the venomous organism Conus striatus. Ixolaris is a potent tick salivary anticoagulant that binds coagulation factor Xa (FXa) and zymogen FX, and forms a quaternary tissue factor (TF)/FVIIa/FX(a)/Ixolaris inhibitory complex. It blocks TF-induced coagulation and PAR2 (proteinase-activated receptor 2) signaling, and prevents thrombosis, tumor growth, and immune activation. Ixolaris consists of 2 Kunitz domains (K1 and K2), both of which recognize the heparin-binding (pro)exosite (HBE) on FX. While K2 is an extraordinarily dynamic domain that encompasses several residues involved in FX binding, K1 domain keeps as a rigid platform supporting the conformational dynamic of the K2 domain, forming a salt bridge with FXa. The structure of this domain is similar to that of Kunitz-type proteinase inhibitors such as BPTI (bovine pancreatic trypsin inhibitor), showing an alpha/beta fold with irregular secondary structure stabilized by three disulfide bonds.


Pssm-ID: 438668  Cd Length: 53  Bit Score: 75.76  E-value: 8.54e-18
                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 442760309 200 CTLPIQNITTCEE-PQERYGYNEKTGQCEEFLG--CADGGNSFEEAEKCWKQC 249
Cdd:cd22625    1 CTLPIQEITTCESqPTKRYGYNKKTQQCEEFLGteCGGGGNSFEEAKECWSSC 53
 
Name Accession Description Interval E-value
Kunitz_ixolaris_1 cd22625
Kunitz-type domain 1 (K1) of Ixolaris, and similar proteins; This model includes the first ...
200-249 8.54e-18

Kunitz-type domain 1 (K1) of Ixolaris, and similar proteins; This model includes the first Kunitz-type domain (K1) of ixolaris from the venomous organism Conus striatus. Ixolaris is a potent tick salivary anticoagulant that binds coagulation factor Xa (FXa) and zymogen FX, and forms a quaternary tissue factor (TF)/FVIIa/FX(a)/Ixolaris inhibitory complex. It blocks TF-induced coagulation and PAR2 (proteinase-activated receptor 2) signaling, and prevents thrombosis, tumor growth, and immune activation. Ixolaris consists of 2 Kunitz domains (K1 and K2), both of which recognize the heparin-binding (pro)exosite (HBE) on FX. While K2 is an extraordinarily dynamic domain that encompasses several residues involved in FX binding, K1 domain keeps as a rigid platform supporting the conformational dynamic of the K2 domain, forming a salt bridge with FXa. The structure of this domain is similar to that of Kunitz-type proteinase inhibitors such as BPTI (bovine pancreatic trypsin inhibitor), showing an alpha/beta fold with irregular secondary structure stabilized by three disulfide bonds.


Pssm-ID: 438668  Cd Length: 53  Bit Score: 75.76  E-value: 8.54e-18
                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 442760309 200 CTLPIQNITTCEE-PQERYGYNEKTGQCEEFLG--CADGGNSFEEAEKCWKQC 249
Cdd:cd22625    1 CTLPIQEITTCESqPTKRYGYNKKTQQCEEFLGteCGGGGNSFEEAKECWSSC 53
Kunitz_SmCI_3-like cd22603
third Kunitz domain of Carboxypeptidase Inhibitor SmCI and similar domains; This group ...
200-249 1.18e-04

third Kunitz domain of Carboxypeptidase Inhibitor SmCI and similar domains; This group includes Sabellastarte magnifica carboxypeptidase inhibitor (SmCI), Bombyx mori cocoon shell-associated trypsin inhibitor (CSTI), Bombus terrestris Kunitz-type serine protease inhibitor Bt-KTI, and similar domains. SmCI is a tri-domain BPTI-Kunitz inhibitor capable of inhibiting serine proteases and A-like metallocarboxypeptidases. While the BPTI-Kunitz family of proteins includes voltage gated channel blockers and inhibitors of serine proteases, SmCI is the only BPTI-Kunitz protein capable of inhibiting metallocarboxypeptidases. Binding studies show that SmCI is able to bind three trypsin molecules under saturating conditions, but only one elastase interacts with the inhibitor. Additionally, SmCI can bind serine proteases and carboxypeptidases at the same time (at least in the ratio 1:1:1), thus becoming the first protease inhibitor that simultaneously blocks these two mechanistic classes of enzymes. CSTI and Bt-KTI are single Kunitz domain proteins that inhibit trypsin; in addition, Bt-KTI also inhibits plasmin. This model contains the third Kunitz domain of SmCI which has a structure similar to those of Kunitz-type proteinase inhibitors such as BPTI (bovine pancreatic trypsin inhibitor), showing an alpha/beta fold with irregular secondary structure stabilized by three disulfide bonds.


Pssm-ID: 438646  Cd Length: 53  Bit Score: 39.34  E-value: 1.18e-04
                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 442760309 200 CTLPIQNiTTCEEPQERYGYNEKTGQCEEFL--GCADGGNSFEEAEKCWKQC 249
Cdd:cd22603    3 CLLPSET-GPCKGSFPRYYYDKETGKCKEFIygGCQGNANNFETKEECERAC 53
Kunitz_KTT cd22620
scorpion venom Kunitz-type toxin (KTT) such as LmKTT-1a, BmKTT-1, and BmKTT-2; This model ...
199-253 4.86e-04

scorpion venom Kunitz-type toxin (KTT) such as LmKTT-1a, BmKTT-1, and BmKTT-2; This model includes scorpion Kunitz-type toxin (KTT) such as Lychas mucronatus LmKTT-1a (also called Delta-KTx 2.1 or SdPII), Mesobuthus martensii BmKTT-1 (also called Delta-KTx 2.4) and BmKTT-2 (also called Delta-KTx 3.1), all expressed by the venom gland. LmKTT-1a, BmKTT-1 and BmKTT-2 are all dual-function toxins that completely inhibit trypsin activity but have no effect on chymotrypsin or elastase. They also inhibit mKv1.3/KCNA3 potassium channel currents. The structures of these domains are similar to those of Kunitz-type proteinase inhibitors such as BPTI (bovine pancreatic trypsin inhibitor); however, they lack the conserved CysII-CysIV disulfide bond but contains 2 cysteine residues at the C-terminus that generate a new disulfide bond.


Pssm-ID: 438663  Cd Length: 58  Bit Score: 37.55  E-value: 4.86e-04
                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 442760309 199 KCTLPIqNITTCEEPQERYGYNEKTGQCEEFL--GCADGGNSFEEAEKCWKQCAPNN 253
Cdd:cd22620    2 DCQLPS-DTGRGKASFTRYYYNEESGKCETFIygGVGGNSNNFLTKEDCCKECAQGS 57
Kunitz_WFIKKN_2-like cd22606
second Kunitz domain of WAP, Kazal, immunoglobulin, Kunitz and NTR domain-containing proteins; ...
200-249 1.06e-03

second Kunitz domain of WAP, Kazal, immunoglobulin, Kunitz and NTR domain-containing proteins; This subfamily includes WAP, Kazal, immunoglobulin, Kunitz and NTR domain-containing protein 1 (WFIKKN1, WFKN1), WFIKKN2 (WFKN2), and similar proteins. WFIKKN proteins are protease inhibitors that contain two distinct Kunitz-type protease inhibitor domains. They may have serine protease- and metalloprotease-inhibitor activity. This model represents the second Kunitz (KU2) domain, which has been shown to inhibit trypsin, but not chymotrypsin, elastase, plasmin, pancreatic kallikrein, lung tryptase, plasma kallikrein, thrombin, urokinase or tissue plasminogen activator. However, the inhibition constant of this domain for bovine trypsin is about five orders of magnitudes lower than that of bovine pancreatic trypsin inhibitor (BPTI) for trypsin. This could be due to unfavorable side-chain conformation of a tryptophan at P2' site which is incompatible with a trypsin complex; typical trypsin inhibitors of the Kunitz family feature a tyrosine residue or other less bulky residues at this site. The structure of KU2 is similar to those of Kunitz-type proteinase inhibitors such as BPTI (bovine pancreatic trypsin inhibitor), showing an alpha/beta fold with irregular secondary structure stabilized by three disulfide bonds.


Pssm-ID: 438649  Cd Length: 53  Bit Score: 36.57  E-value: 1.06e-03
                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 442760309 200 CTLPIQNiTTCEEPQERYGYNEKTGQCEEFL--GCADGGNSFEEAEKCWKQC 249
Cdd:cd22606    2 CSLPAVQ-GPCKAWEPRWAYNSLLKQCQSFVygGCEGNENNFESKEACEDAC 52
Kunitz_TKDP-like cd22609
trophoblast Kunitz domain protein (TKDP) and similar proteins; This model contains the ...
210-249 2.03e-03

trophoblast Kunitz domain protein (TKDP) and similar proteins; This model contains the trophoblast Kunitz domain protein 1 (TKDP-1) and splice variant TKDP-4, among others, which are Kunitz inhibitor domain proteins. TKDP-1 is expressed in the trophectoderm which forms the outer epithelial layer of the trophoblast, and may play a role in mediating maternal-conceptus interactions in the immediate preimplantation period. However, it does not appear to have proteinase inhibitory activity. These domains are similar to those of Kunitz-type proteinase inhibitors such as BPTI (bovine pancreatic trypsin inhibitor) that shows an alpha/beta fold with irregular secondary structure stabilized by three disulfide bonds.


Pssm-ID: 438652  Cd Length: 52  Bit Score: 35.89  E-value: 2.03e-03
                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 442760309 210 CEEPQERYGYNEKTGQCEEFL--GCADGGNSFEEAEKCWKQC 249
Cdd:cd22609   11 CKASMTRYFYNAQTGHCEQFVygGCGGNRNNFLTLEDCMKTC 52
Kunitz_TFPI1_1-like cd22613
Kunitz protease inhibitor (KPI) domain 1 (KPI-1 or K1) of tissue factor pathway inhibitor ...
210-249 2.62e-03

Kunitz protease inhibitor (KPI) domain 1 (KPI-1 or K1) of tissue factor pathway inhibitor (TFPI); This model represents the first Kunitz-type domain (K1 or KPI-1) of tissue factor pathway inhibitor (TFPI or TFPI1), also known as extrinsic pathway inhibitor (EPI) or lipoprotein-associated coagulation inhibitor (LACI). TFPI down-regulates the extrinsic coagulation pathway via inhibition of activated factor X (FXa or Xa) and FVIIa (VIIa). It inhibits activated FXa via a "slow-tight binding mechanism", i.e. rapid formation of a loose FXa-TFPI complex that then slowly isomerizes to a tight FXa-TFPI* complex. Subsequent inhibition of FVIIa is facilitated by the presence of tissue factor (TF) and FXa, which together rapidly and efficiently form a quaternary FXa-TFPI-TF-FVIIa complex in which the activity of FXa and FVIIa are inhibited. TFPI consists of 3 Kunitz-type protease inhibitor (KPI) domains in a tandem arrangement; The K1 domain of TFPI has been shown to bind and inhibit FVIIa while the K2 domain similarly inhibits FXa. Small peptide blocking inhibition of FXa and TF-FVIIa by TFPI shows that domain K1 is not only important for FVIIa inhibition but also for FXa inhibition, i.e. for the transition of the loose to the tight FXa-TFPI complex. The structure of the K1 domain is similar to those of other Kunitz-type proteinase inhibitors such as BPTI (bovine pancreatic trypsin inhibitor), showing an alpha/beta fold with irregular secondary structure stabilized by three disulfide bonds.


Pssm-ID: 438656  Cd Length: 55  Bit Score: 35.41  E-value: 2.62e-03
                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 442760309 210 CEEPQERYGYNEKTGQCEEFL--GCADGGNSFEEAEKCWKQC 249
Cdd:cd22613   13 CKAIMKRFFFNIFTRQCEEFIygGCEGNENRFETLEECKKTC 54
Kunitz_BPTI cd22592
bovine pancreatic trypsin inhibitor; This model contains bovine pancreatic trypsin inhibitor ...
216-249 4.19e-03

bovine pancreatic trypsin inhibitor; This model contains bovine pancreatic trypsin inhibitor (BPTI, also known as pancreatic Kunitz inhibitor, aprotinin, or trypsin-kallikrein inhibitor), a small protein that inhibits the action of the trypsin, and is thus a member of the serine protease family of inhibitors. This class of enzymes contains conserved cysteine residues that form 3 disulfide bonds to stabilize the three-dimensional structure. BPTI has a relatively broad specificity, inhibiting trypsin as well as chymotrypsin, and elastase-like serine (pro)enzymes capable of very different primary specificity. It reacts rapidly with serine proteases to form stable complexes, but the enzyme:inhibitor complex formation may involve several intermediates corresponding to discrete reaction steps. Furthermore, BPTI inhibits the nitric oxide synthase type-I and -II action, and impairs K+ transport by Ca2+-activated K+ channels. Clinically, BPTI is used in certain surgical interventions, such as cardiopulmonary surgery and orthotopic liver transplantation since it significantly reduces hemorrhagic complications.


Pssm-ID: 438635  Cd Length: 52  Bit Score: 34.93  E-value: 4.19e-03
                         10        20        30
                 ....*....|....*....|....*....|....*.
gi 442760309 216 RYGYNEKTGQCEEFL--GCADGGNSFEEAEKCWKQC 249
Cdd:cd22592   17 RYFYNAKSGLCETFVygGCRAKRNNFLSAEDCMRTC 52
 
Blast search parameters
Data Source: Precalculated data, version = cdd.v.3.21
Preset Options:Database: CDSEARCH/cdd   Low complexity filter: no  Composition Based Adjustment: yes   E-value threshold: 0.01

References:

  • Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
  • Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
  • Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
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