Reviewed, UniProtKB/Swiss-Prot P28590 (ABRC_ABRPR)

Names and origin

Protein names	Recommended name:     Abrin-c Cleaved into the following 3 chains:     1- Recommended name:             Abrin-c A chain               EC=3.2.2.22         Alternative name(s):             rRNA N-glycosidase     2- Recommended name:             Linker peptide     3- Recommended name:             Abrin-c B chain
Organism	Abrus precatorius (Indian licorice) (Crab's eye)
Taxonomic identifier	3816 [NCBI]
Taxonomic lineage	Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › eurosids I › Fabales › Fabaceae › Papilionoideae › Abreae › Abrus

Protein attributes

Sequence length	562 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. Abrin-a is more toxic than ricin. The B chain is a galactose-specific lectin that facilitates the binding of abrin to the cell membrane that precedes endocytosis.
Catalytic activity	Endohydrolysis of the N-glycosidic bond at one specific adenosine on the 28S rRNA.
Subunit structure	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).
Sequence similarities	In the N-terminal section; belongs to the ribosome-inactivating protein family. Type 2 RIP subfamily. Contains 2 ricin B-type lectin domains.

Ontologies

Keywords
Biological process	Plant defense
Domain	Repeat Signal
Ligand	Lectin
Molecular function	Hydrolase Protein synthesis inhibitor Toxin
PTM	Disulfide bond Glycoprotein Pyrrolidone carboxylic acid
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological process	defense response Inferred from electronic annotation. Source: UniProtKB-KW negative regulation of translation Inferred from electronic annotation. Source: UniProtKB-KW pathogenesis Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	rRNA N-glycosylase activity Inferred from electronic annotation. Source: EC sugar binding Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Signal peptide	1 – 34	34	By similarity
	Chain	35 – 285	251	Abrin-c A chain By similarity		PRO_0000030735
	Peptide	286 – 295	10	Linker peptide By similarity		PRO_0000030736
	Chain	296 – 562	267	Abrin-c B chain By similarity		PRO_0000030737
Regions
	Domain	307 – 434	128	Ricin B-type lectin 1
	Repeat	317 – 359	43	1-alpha
	Repeat	360 – 400	41	1-beta
	Repeat	403 – 435	33	1-gamma
	Domain	437 – 561	125	Ricin B-type lectin 2
	Repeat	448 – 483	36	2-alpha
	Repeat	487 – 526	40	2-beta
	Repeat	529 – 562	34	2-gamma
Sites
	Active site	198	1	By similarity
Amino acid modifications
	Modified residue	35	1	Pyrrolidone carboxylic acid By similarity
	Glycosylation	234	1	N-linked (GlcNAc...) Potential
	Glycosylation	395	1	N-linked (GlcNAc...) Potential
	Glycosylation	435	1	N-linked (GlcNAc...) Potential
	Disulfide bond	281 ↔ 303		Interchain (between A and B chains) By similarity
	Disulfide bond	320 ↔ 339		By similarity
	Disulfide bond	363 ↔ 380		By similarity
	Disulfide bond	451 ↔ 464		By similarity
	Disulfide bond	490 ↔ 507		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P28590-1 [UniParc]. Last modified December 1, 1992. Version 1. Checksum: 1FD0ABC7D7BA6278	FASTA	562	62,818
	10 20 30 40 50 60 MDKTLKLLIL CLAWTCSFSA LRCAARTYPP VATNQDQVIK FTTEGATSQS YKQFIEALRQ 70 80 90 100 110 120 RLTGGLIHDI PVLPDPTTVE ERNRYITVEL SNSERESIEV GIDVTNAYVV AYRAGSQSYF 130 140 150 160 170 180 LRDAPASAST YLFPGTQRYS LRFDGSYGDL ERWAHQTREE ISLGLQALTH AISFLRSGAS 190 200 210 220 230 240 NDEEKARTLI VIIQMASEAA RYRYISNRVG VSIRTGTAFQ PDPAMLSLEN NWDNLSGGVQ 250 260 270 280 290 300 QSVQDTFPNN VILSSINRQP VVVDSLSHPT VAVLALMLFV CNPPNANQSP LLIRSIVEES 310 320 330 340 350 360 KICSSRYEPT VRIGGRDGMC VDVYDDGYHN GNRIIAWKCK DRLEENQLWT LKSDKTIRSN 370 380 390 400 410 420 GKCLTTEGYA PGNYVMIYDC TSAVAEATYW EIWDNGTIIN PKSALVLSAE SSSMGGTLTV 430 440 450 460 470 480 QTNEYLMRQG WRTGNNTSPF VTSISGYSDL CMQAQGSNVW LADCDNNKKE QQWALYTDGS 490 500 510 520 530 540 IRSVQNTNNC LTSKDHKQGS PIVLMACSNG WASQRWLFKN DGSIYNLHDD MVMDVKRSDP 550 560 SLKEIILHPY HGKPNQIWLT LF

References

[1]	"Preproabrin: genomic cloning, characterisation and the expression of the A-chain in Escherichia coli." Wood K.A., Lord J.M., Wawrzynczak E.J., Piatak M. Eur. J. Biochem. 198:723-732(1991) [PubMed: 2050149] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Tissue: Leaf.
[2]	"Detection and partial characterization of lectin from Abrus precatorius.L." Ingale A.G. Submitted (APR-2009) to UniProtKB Cited for: PARTIAL PROTEIN SEQUENCE, FUNCTION. Strain: GIS04. Tissue: Seed.

Cross-references

Sequence databases
EMBLGenBankDDBJ	X55667 Genomic DNA. Translation: CAA39202.1.
PIR	S16022.
3D structure databases
HSSP	HSSP built from PDB template 1ABR based on UniProtKB P11140.
SMR	P28590. Positions 35-285, 296-562.
ModBase	Search...
Enzyme and pathway databases
BRENDA	3.2.2.22. 273549.
Family and domain databases
InterPro	IPR001574. Ribosome_inactivat_prot. IPR017988. Ribosome_inactivat_prot_CS. IPR016138. Ribosome_inactivat_prot_sub1. IPR016139. Ribosome_inactivat_prot_sub2. IPR017989. Ribosome_inactivat_prot_subgr. IPR000772. Ricin_B_lectin. [Graphical view]
Gene3D	G3DSA:3.40.420.10. Ribosome_inactivat_prot_sub1. 1 hit. G3DSA:4.10.470.10. Ribosome_inactivat_prot_sub2. 1 hit.
Pfam	PF00652. Ricin_B_lectin. 2 hits. PF00161. RIP. 1 hit. [Graphical view]
PRINTS	PR00396. SHIGARICIN.
SMART	SM00458. RICIN. 2 hits. [Graphical view]
PROSITE	PS50231. RICIN_B_LECTIN. 2 hits. PS00275. SHIGA_RICIN. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

ABRC_ABRPR

Accession

Primary (citable) accession number: P28590

Entry history

Integrated into UniProtKB/Swiss-Prot:	December 1, 1992
Last sequence update:	December 1, 1992
Last modified:	June 16, 2009
This is version 66 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)