SCPSCP / Tpx-1 / Ag5 / PR-1 / Sc7 family of extracellular domains. |
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| SMART accession number: | SM00198
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| Description: |
Human glioma pathogenesis-related protein GliPR and the plant pathogenesis-related protein represent functional links between plant defense systems and human immune system. This family has no known function. |
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| Interpro abstract (IPR001283): |
A number of eukaryotic extracellular proteins have been shown to be evolutionarily related. The family includes rodent sperm-coating glycoprotein (or acidic epididymal glycoprotein), which is thought to be involved in sperm maturation [(PUBMED:1301383)]; mammalian testis-specific protein (Tpx-1) [(PUBMED:2613236)]; glioma pathogenesis-related protein; lizard helothermine, a toxin that blocks ryanodine receptors; venom allergen 5 from vespid wasps and venom allergen 3 from fire ants, which are potent allergens that mediate allergic reactions to stings insects of the Hymenoptera family [(PUBMED:8454859)]; plant pathogenesis proteins of the PR-1 family [(PUBMED:2026137)], which are synthesised during pathogen infection or other stress-related responses; proteins Sc7 and Sc14 from the basidiomycete fungus Schizophyllum commune, which are loosely associated with fruiting body hyphal walls [(PUBMED:8245835)]; ancylostoma secreted protein from dog hookworm; and yeast hypothetical proteins YJL078c, YJL079c and YKR013w. The precise functions of these proteins is still unclear.
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| Family alignment: |
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There are 2007
SCP domains in 1909 proteins in SMART's nrdb database.
Click on the following links for more information.
- Evolution (species in which this domain is found)
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- Literature (relevant references for this domain)
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Primary literature is listed below; Automatically-derived, secondary literature is also avaliable.
- Ponting CP, Aravind L, Schultz J, Bork P, Koonin EV
- Eukaryotic signalling domain homologues in archaea and bacteria. Ancient ancestry and horizontal gene transfer.
- J Mol Biol. 1999; 289: 729-45
- Display abstract
Phyletic distributions of eukaryotic signalling domains were studied using recently developed sensitive methods for protein sequence analysis, with an emphasis on the detection and accurate enumeration of homologues in bacteria and archaea. A major difference was found between the distributions of enzyme families that are typically found in all three divisions of cellular life and non-enzymatic domain families that are usually eukaryote-specific. Previously undetected bacterial homologues were identified for# plant pathogenesis-related proteins, Pad1, von Willebrand factor type A, src homology 3 and YWTD repeat-containing domains. Comparisons of the domain distributions in eukaryotes and prokaryotes enabled distinctions to be made between the domains originating prior to the last common ancestor of all known life forms and those apparently originating as consequences of horizontal gene transfer events. A number of transfers of signalling domains from eukaryotes to bacteria were confidently identified, in contrast to only a single case of apparent transfer from eukaryotes to archaea.
- Szyperski T, Fernandez C, Mumenthaler C, Wuthrich K
- Structure comparison of human glioma pathogenesis-related protein GliPR and the plant pathogenesis-related protein P14a indicates a functional link between the human immune system and a plant defense system.
- Proc Natl Acad Sci U S A. 1998; 95: 2262-6
- Display abstract
The human glioma pathogenesis-related protein (GliPR) is highly expressed in the brain tumor glioblastoma multiforme and exhibits 35% amino acid sequence identity with the tomato pathogenesis-related (PR) protein P14a, which has an important role for the plant defense system. A molecular model of GliPR was computed with the distance geometry program DIANA on the basis of a P14a-GliPR sequence alignment and a set of 1,200 experimental NMR conformational constraints collected with P14a. The GliPR structure is represented by a group of 20 conformers with small residual DIANA target function values, low AMBER-energies after restrained energy-minimization with the program OPAL, and an average rms deviation relative to the mean of 1.6 A for the backbone heavy atoms. Comparison of the GliPR model with the P14a structure lead to the identification of a common partially solvent-exposed spatial cluster of four amino acid residues, His-69, Glu-88, Glu-110, and His-127 in the GliPR numeration. This cluster is conserved in all known plant PR proteins of class 1, indicating a common putative active site for GliPR and PR-1 proteins and thus a functional link between the human immune system and a plant defense system.
- Fernandez C, Szyperski T, Bruyere T, Ramage P, Mosinger E, Wuthrich K
- NMR solution structure of the pathogenesis-related protein P14a.
- J Mol Biol. 1997; 266: 576-93
- Display abstract
The nuclear magnetic resonance (NMR) structure of the 15 kDa pathogenesis-related protein P14a, which displays antifungicidal activity and is induced in tomato leaves as a response to pathogen infection, was determined using 15N/13C doubly labeled and unlabeled protein samples. In all, 2030 conformational constraints were collected as input for the distance geometry program DIANA. After energy-minimization with the program OPAL the 20 best conformers had an average root-mean-square deviation value relative to the mean coordinates of 0.88 A for the backbone atoms N, C(alpha) and C', and 1.30 A for all heavy atoms. P14a contains four alpha-helices (I to IV) comprising residues 4 to 17, 27 to 40, 64 to 72 and 93 to 98, a short 3(10)-helix of residues 73 to 75 directly following helix III, and a mixed, four-stranded beta-sheet with topology +3x, -2x, +1, containing the residues 24-25, 53 to 58, 104 to 111 and 117 to 124. These regular secondary structure elements form a novel, complex alpha + beta topology in which the alpha-helices I, III and IV and the 3(10)-helix are located above the plane defined by the beta-sheet, and the alpha-helix II lies below this plane. The alpha-helices and beta-strands are thus arranged in three stacked layers, which are stabilized by two distinct hydrophobic cores associated with the two layer interfaces, giving rise to an "alpha-beta-alpha sandwich". The three-dimensional structure of P14a provides initial leads for identification of the so far unknown active sites and the mode of action of the protein, which is of direct interest for the generation of transgenic plants with improved host defense properties.
- Stintzi A et al.
- Plant 'pathogenesis-related' proteins and their role in defense against pathogens.
- Biochimie. 1993; 75: 687-706
- Display abstract
The hypersensitive reaction to a pathogen is one of the most efficient defense mechanisms in nature and leads to the induction of numerous plant genes encoding defense proteins. These proteins include: 1) structural proteins that are incorporated into the extracellular matrix and participate in the confinement of the pathogen; 2) enzymes of secondary metabolism, for instance those of the biosynthesis of plant antibiotics; 3) pathogenesis-related (PR) proteins which represent major quantitative changes in soluble protein during the defense response. The PRs have typical physicochemical properties that enable them to resist to acidic pH and proteolytic cleavage and thus survive in the harsh environments where they occur: vacuolar compartment or cell wall or intercellular spaces. Since the discovery of the first PRs in tobacco many other similar proteins have been isolated from tobacco but also from other plant species, including dicots and monocots, the widest range being characterized from hypersensitively reacting tobacco. Based first on serological properties and later on sequence data, the tobacco PRs have been classified in five major groups. Group PR-1 contains the first discovered PRs of 15-17 kDa molecular mass, whose biological activity is still unknown, but some members have been shown recently to have antifungal activity. Group PR-2 contains three structurally distinct classes of 1,3-beta-glucanases, with acidic and basic counterparts, with dramatically different specific activity towards linear 1,3-beta-glucans and with different substrate specificity. Group PR-3 consists of various chitinases-lysozymes that belong to three distinct classes, are vacuolar or extracellular, and exhibit differential chitinase and lysozyme activities. Some of them, either alone or in combination with 1,3-beta-glucanases, have been shown to be antifungal in vitro and in vivo (transgenic plants), probably by hydrolysing their substrates as structural components in the fungal cell wall. Group PR-4 is the less studied, and in tobacco contains four members of 13-14.5 kDa of unknown activity and function. Group PR-5 contains acidic-neutral and very basic members with extracellular and vacuolar localization, respectively, and all members show sequence similarity to the sweet-tasting protein thaumatin. Several members of the PR-5 group from tobacco and other plant species were shown to display significant in vitro activity of inhibiting hyphal growth or spore germination of various fungi probably by a membrane permeabilizing mechanism.(ABSTRACT TRUNCATED AT 400 WORDS)
- Structure (3D structures containing this domain)
3D Structures of SCP domains in PDB
| PDB code | Main view | Title | | 1cfe |  | P14a, nmr, 20 structures |
| 1qnx |  | Ves v 5, an allergen from vespula vulgaris venom |
| 1rc9 |  | Crystal structure of stecrisp, a member of crisp family from trimeresurus stejnegeri refined at 1.6 angstroms resolution: structual relationship of the two domains |
| 1smb |  | Crystal structure of golgi-associated pr-1 protein |
| 1u53 |  | Novel x-ray structure of na-asp-2, a pr-1 protein from the nematode parasite necator americanus and a vaccine antigen for human hookworm infection |
| 1wvr |  | Crystal structure of a crisp family ca-channel blocker derived from snake venom |
| 1xta |  | Crystal structure of natrin, a snake venom crisp from taiwan cobra (naja atra) |
| 1xx5 |  | Crystal structure of natrin from naja atra snake venom |
| 2dda |  | Crystal structure of pseudechetoxin from pseudechis australis |
| 2ddb |  | Crystal structure of pseudecin from pseudechis porphyriacus |
| 2epf |  | Crystal structure of zinc-bound pseudecin from pseudechis porphyriacus |
| 2giz |  | Structural and functional analysis of natrin, a member of crisp-3 family blocks a variety of ion channels |
| 2vzn |  | Crystal structure of the major allergen from fire ant venom, sol i 3 |
- Links (links to other resources describing this domain)
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