Summary: Legume lectin domain
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This is the Wikipedia entry entitled "Leguminous lectin family". More...
Leguminous lectin family Edit Wikipedia article
Lectin_legB | |||||||||
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![]() x-ray crystal structure of a pea lectin-trimannoside complex at 2.6 angstroms resolution
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Identifiers | |||||||||
Symbol | Lectin_legB | ||||||||
Pfam | PF00139 | ||||||||
Pfam clan | CL0004 | ||||||||
InterPro | IPR001220 | ||||||||
PROSITE | PDOC00278 | ||||||||
SCOP | 1lem | ||||||||
SUPERFAMILY | 1lem | ||||||||
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In molecular biology, the leguminous lectin family is a family of lectin proteins.
It is one of the largest lectin families with more than 70 lectins reported in a review in 1990.[1] Leguminous lectins consist of two or four subunits, each containing one carbohydrate-binding site. The interaction with sugars requires tightly bound calcium and manganese ions. The structural similarities of these lectins are reported by the primary structural analyses and X-ray crystallographic studies.[2][3] X-ray studies have shown that the folding of the polypeptide chains in the region of the carbohydrate-binding sites is also similar, despite differences in the primary sequences. The carbohydrate-binding sites of these lectins consist of two conserved amino acids on beta pleated sheets. One of these loops contains transition metals, calcium and manganese, which keep the amino acid residues of the sugar-binding site at the required positions. Amino acid sequences of this loop play an important role in the carbohydrate-binding specificities of these lectins. These lectins bind either glucose, mannose or galactose. The exact function of legume lectins is not known but they may be involved in the attachment of nitrogen-fixing bacteria to legumes and in the protection against pathogens.[4][5]
Some legume lectins are proteolytically processed to produce two chains, beta (which corresponds to the N-terminal) and alpha (C-terminal). The lectin concanavalin A (conA) from jack bean is exceptional in that the two chains are transposed and ligated (by formation of a new peptide bond). The N terminus of mature conA thus corresponds to that of the alpha chain and the C terminus to the beta chain.[6]
References
- ^ Sharon N, Lis H (1990). "Legume lectins--a large family of homologous proteins.". FASEB J. 4 (14): 3198–208. PMID 2227211.
- ^ de Oliveira TM, Delatorre P, da Rocha BA, de Souza EP, Nascimento KS, Bezerra GA, et al. (2008). "Crystal structure of Dioclea rostrata lectin: insights into understanding the pH-dependent dimer-tetramer equilibrium and the structural basis for carbohydrate recognition in Diocleinae lectins.". J Struct Biol. 164 (2): 177–82. PMID 18682294. doi:10.1016/j.jsb.2008.05.012.
- ^ Rozwarski DA, Swami BM, Brewer CF, Sacchettini JC (1998). "Crystal structure of the lectin from Dioclea grandiflora complexed with core trimannoside of asparagine-linked carbohydrates.". J Biol Chem. 273 (49): 32818–25. PMID 9830028. doi:10.1074/jbc.273.49.32818.
- ^ Roopashree S, Singh SA, Gowda LR, Rao AG (2006). "Dual-function protein in plant defence: seed lectin from Dolichos biflorus (horse gram) exhibits lipoxygenase activity.". Biochem J. 395 (3): 629–39. PMC 1462680
. PMID 16441240. doi:10.1042/BJ20051889.
- ^ Beringer JE, Brewin N, Johnston AW, Schulman HM, Hopwood DA (1979). "The Rhizobium--legume symbiosis.". Proc R Soc Lond B Biol Sci. 204 (1155): 219–33. PMID 36624. doi:10.1098/rspb.1979.0024.
- ^ Carrington DM, Auffret A, Hanke DE (1985). "Polypeptide ligation occurs during post-translational modification of concanavalin A.". Nature. 313 (5997): 64–7. PMID 3965973. doi:10.1038/313064a0.
This article incorporates text from the public domain Pfam and InterPro IPR001220
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Legume lectin domain Provide feedback
No Pfam abstract.
Internal database links
SCOOP: | Bact_lectin Lectin_leg-like |
Similarity to PfamA using HHSearch: | Lectin_leg-like Bact_lectin |
External database links
HOMSTRAD: | ltn |
PROSITE: | PDOC00278 |
SCOP: | 1lem |
This tab holds annotation information from the InterPro database.
InterPro entry IPR001220
Lectins are carbohydrate-binding proteins. Leguminous lectins form one of the largest lectin families and resemble each other in their physicochemical properties, though they differ in their carbohydrate specificities. They bind either glucose/mannose or galactose [PUBMED:2227211]. Carbohydrate-binding activity depends on the simultaneous presence of both a calcium and a transition metal ion [PUBMED:9546043]. The exact function of legume lectins is not known, but they may be involved in the attachment of nitrogen-fixing bacteria to legumes and in the protection against pathogens [PUBMED:16441240, PUBMED:36624].
Some legume lectins are proteolytically processed to produce two chains, beta (which corresponds to the N-terminal) and alpha (C-terminal) [PUBMED:8373823]. The lectin concanavalin A (conA) from jack bean is exceptional in that the two chains are transposed and ligated (by formation of a new peptide bond). The N terminus of mature conA thus corresponds to that of the alpha chain and the C terminus to the beta chain [PUBMED:3965973]. Though the legume lectins monomer is structurally well conserved, their quaternary structures vary widely [PUBMED:9546043].
Gene Ontology
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Molecular function | carbohydrate binding (GO:0030246) |
Domain organisation
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
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Pfam Clan
This family is a member of clan Concanavalin (CL0004), which has the following description:
This superfamily includes a diverse range of carbohydrate binding domains and glycosyl hydrolase enzymes that share a common structure.
The clan contains the following 49 members:
Alginate_lyase2 ArabFuran-catal Arabino_trans_N Bac_rhamnosid Bact_lectin bCoV_S1_N Calreticulin Cleaved_Adhesin DUF1080 DUF1349 DUF1583 DUF1961 DUF2401 DUF3472 DUF4975 Exotox-A_bind Gal-bind_lectin GalBD_like GH131_N GH43_C2 Glyco_hydro_11 Glyco_hydro_12 Glyco_hydro_16 Glyco_hydro_32C Glyco_hydro_7 HA1 Laminin_G_1 Laminin_G_2 Laminin_G_3 Lectin_leg-like Lectin_legB MAM Methyltransf_FA Neuralized Pentaxin Peptidase_A4 Polysacc_lyase PRY Reoviridae_Vp9 Sial-lect-inser Sialidase SKN1 SPRY TgMIC1 Toxin_R_bind_N TSP_C VP4_haemagglut XET_C YrpDAlignments
We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the UniProtKB sequence database, the NCBI sequence database, and our metagenomics sequence database. More...
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We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.
Seed (81) |
Full (6275) |
Representative proteomes | UniProt (9610) |
NCBI (14244) |
Meta (45) |
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RP15 (315) |
RP35 (3120) |
RP55 (5146) |
RP75 (6480) |
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PP/heatmap | 1 |
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
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Seed (81) |
Full (6275) |
Representative proteomes | UniProt (9610) |
NCBI (14244) |
Meta (45) |
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RP15 (315) |
RP35 (3120) |
RP55 (5146) |
RP75 (6480) |
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Raw Stockholm | |||||||||
Gzipped |
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
HMM logo
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Trees
This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.
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Curation and family details
This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.
Curation
Seed source: | Prosite |
Previous IDs: | lectin_legB; |
Type: | Domain |
Sequence Ontology: | SO:0000417 |
Author: |
Sonnhammer ELL |
Number in seed: | 81 |
Number in full: | 6275 |
Average length of the domain: | 222.50 aa |
Average identity of full alignment: | 29 % |
Average coverage of the sequence by the domain: | 39.37 % |
HMM information
HMM build commands: |
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 47079205 -E 1000 --cpu 4 HMM pfamseq
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Model details: |
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Model length: | 249 | ||||||||||||
Family (HMM) version: | 20 | ||||||||||||
Download: | download the raw HMM for this family |
Species distribution
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Selections
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Interactions
Structures
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Lectin_legB domain has been found. There are 1006 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.
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