PPepDB-ID	"Peptide Name"	PMID	"Plant source"	"Plant Family"	"Peptide Family"	"Peptide function"	"Peptide function description"	"Activity against"	Sequence	"Sequence Length"	Validation	"Avg. Molecular wt(Da)"	"Monoisotopic molecular wt(Da)"	pI	Method	"Additional information"
PPepDB_4153	RICI_RICCO	--NA--	"Ricinus communis"	Euphorbiaceae	--NA--	Signaling-peptide	"3D-structure; Direct protein sequencing; Glycoprotein; Hydrolase; Lectin; Nucleotide-binding; Plant defense; Protein synthesis inhibitor; Repeat; Signal; Toxin | Ricin precursor [Contains: Ricin A chain (EC 3.2.2.22) (rRNA N-,glycosidase); Linker peptide; Ricin B chain]."	--NA--	AELSVTLALDVTNAYVVGYRAGNSAYFFHPDNQEDAEAITHLFTDVQNRYASDPSLKQIILYPLHGDPNQIWLPLFATRWQIWDNGTIINPRSSLVLAATSGNSGTTLTVQTNIYAVSQGWLPTNNATVQSYTNFIRAVRGRLTTGADVRHEIPVLPNRVGLPINQRFILVELSNHMKPGGNTIVIWMYAVATWLCFGSTSGWSFTLEDNNIFPKQYPIINFTTAGQFSLLIRPVVPNFNADVCMDPEPIVRIVGRNGLCVDVRDGRFHNGNAIQLRDNCLTSDSNIRETVVKILSCGPASSGQRWMFKNDGTILNLYSGLVLDVRRSFIICIQMISEAARFQYIEGEMRTRIRYNRRSAPDPSVITLENSWGRLSTAIQESNQGAFASPIQLQRRNGSKFSVYDVSILIPIIALMVYRCAPPPSSTFAFGGNYDRLEQLAGNLRENIELGNGPLEEAISALYYYSTGGTQLPTLATQPFVTTIVGLYGLCLQANSGQVWIEDCSSEKAEQQWALYADGSIRPQQNWPCKSNTDANQLWTLKRDNTIRSNGKCLTTYGYSPGVYVMIYDCNTAATD	576	"Experimental evidence at protein level"	64090.57	64050.2	6.37	--NA--	"FUNCTION:Ricin is highly toxic to animal cells and to a lesser extent to plant cells. The 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.The A chain can inactivate a few thousand ribosomes per minute, faster than the cell can make new ones. Therefore a single A chain molecule can kill an animal cell. The 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; B chains are also responsible for cell agglutination (Lectin activity).CATALYTIC ACTIVITY:Endohydrolysis of the N-glycosidic bond at one specific adenosine on the 28S rRNA.SUBUNIT:Disulfide-linked dimer of A and B chains.DOMAIN:The B chain is composed of two domains, each domain consists of 3 homologous subdomains (alpha, beta, gamma).BIOTECHNOLOGY:A deglycosylated A chain 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.SIMILARITY:Contains 2 ricin B-type lectin domains.SEQUENCE CAUTION:Sequence=Ref.4; Type=Miscellaneous discrepancy; Note=High number of conflicts with the sequence translated from DNA; Sequence=Ref.5; Type=Miscellaneous discrepancy; Note=High number of conflicts with the sequence translated from DNA;WEB RESOURCE:Name=Protein Spotlight; Note=Baneful beans - Issue 31 of February 2003; URL=""http://www.expasy.org/spotlight/back_issues/sptlt031.shtml""; "