UniProt functional annotation for P02879



	UniProt functional annotation for P02879

UniProt code: P02879.

Organism: Ricinus communis (Castor bean).

Taxonomy: Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta; Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae; rosids; fabids; Malpighiales; Euphorbiaceae; Acalyphoideae; Acalypheae; Ricinus.

Function: Ricin is highly toxic to animal cells, and to a lesser extent to plant cells.

Function: [Ricin A chain]: Acts as a glycosidase that removes a specific adenine residue from an exposed loop of the 28S rRNA (A4324 in mammals), leading to rRNA breakage. As this loop is involved in elongation factor binding, modified ribosomes are catalytically inactive and unable to support protein synthesis. Can inactivate a few thousand ribosomes per minute, faster than the cell can make new ones. Therefore a single molecule can kill an animal cell.

Function: [Ricin B chain]: Binds to beta-D-galactopyranoside moieties on cell surface glycoproteins and glycolipids and facilitates the entry into the cell of the A chain. Also responsible for cell agglutination (Lectin activity).

Catalytic activity: [Ricin A chain]: Reaction=Endohydrolysis of the N-glycosidic bond at one specific adenosine on the 28S rRNA.; EC=3.2.2.22;

Subunit: Disulfide-linked dimer of A and B chains.

Domain: [Ricin B chain]: Composed of two domains, each domain consists of 3 homologous subdomains (alpha, beta, gamma).

Biotechnology: [Ricin A chain]: A deglycosylated form may be linked to monoclonal antibodies to produce immunotoxins exploited in cancer treatment. However, a point mutation should be introduced to eliminate vascular leak syndrome, a side effect resulting from endothelial damage.

Similarity: In the N-terminal section; belongs to the ribosome- inactivating protein family. Type 2 RIP subfamily. {ECO:0000305}.

Sequence caution: Sequence=Ref.4; Type=Miscellaneous discrepancy; Note=High number of conflicts with the sequence translated from DNA.; Evidence={ECO:0000305}; Sequence=Ref.5; Type=Miscellaneous discrepancy; Note=High number of conflicts with the sequence translated from DNA.; Evidence={ECO:0000305};

Annotations taken from UniProtKB at the EBI.


Organism:		Ricinus communis (Castor bean).
Taxonomy:		Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta; Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae; rosids; fabids; Malpighiales; Euphorbiaceae; Acalyphoideae; Acalypheae; Ricinus.



Function:		Ricin is highly toxic to animal cells, and to a lesser extent to plant cells.



Function:		[Ricin A chain]: Acts as a glycosidase that removes a specific adenine residue from an exposed loop of the 28S rRNA (A4324 in mammals), leading to rRNA breakage. As this loop is involved in elongation factor binding, modified ribosomes are catalytically inactive and unable to support protein synthesis. Can inactivate a few thousand ribosomes per minute, faster than the cell can make new ones. Therefore a single molecule can kill an animal cell.



Function:		[Ricin B chain]: Binds to beta-D-galactopyranoside moieties on cell surface glycoproteins and glycolipids and facilitates the entry into the cell of the A chain. Also responsible for cell agglutination (Lectin activity).


Catalytic activity:		[Ricin A chain]: Reaction=Endohydrolysis of the N-glycosidic bond at one specific adenosine on the 28S rRNA.; EC=3.2.2.22;
Subunit:		Disulfide-linked dimer of A and B chains.
Domain:		[Ricin B chain]: Composed of two domains, each domain consists of 3 homologous subdomains (alpha, beta, gamma).
Biotechnology:		[Ricin A chain]: A deglycosylated form may be linked to monoclonal antibodies to produce immunotoxins exploited in cancer treatment. However, a point mutation should be introduced to eliminate vascular leak syndrome, a side effect resulting from endothelial damage.
Similarity:		In the N-terminal section; belongs to the ribosome- inactivating protein family. Type 2 RIP subfamily. {ECO:0000305}.
Sequence caution:		Sequence=Ref.4; Type=Miscellaneous discrepancy; Note=High number of conflicts with the sequence translated from DNA.; Evidence={ECO:0000305}; Sequence=Ref.5; Type=Miscellaneous discrepancy; Note=High number of conflicts with the sequence translated from DNA.; Evidence={ECO:0000305};