1AHB

THE N-GLYCOSIDASE MECHANISM OF RIBOSOME-INACTIVATING PROTEINS IMPLIED BY CRYSTAL STRUCTURES OF ALPHA-MOMORCHARIN

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: SCOP2 Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Structure Motif: Primary M-CSA Annotation

Domain Annotation: SCOP/SCOPe Classification SCOP Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1ahba_	Alpha and beta proteins (a+b)	Ribosome inactivating proteins (RIP)	Ribosome inactivating proteins (RIP)	Plant cytotoxins	alpha-Momorcharin (momordin)	balsam pear (Momordica charantia ) [TaxId: 3673 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	Ribosome inactivating proteins (RIP)	8036972	3001164	SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	RIP	e1ahbA1	A: a+b two layers	X: RIP/Polo-box domain	H: Ribosome inactivating proteins (RIP) (From Topology)	T: Ribosome inactivating proteins (RIP)	F: RIP	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.40.420.10	Alpha Beta	3-Layer(aba) Sandwich	Ricin (A subunit)	domain 1	CATH (4.3.0)
A	4.10.470.10	Few Secondary Structures	Irregular	Ricin (A Subunit), domain 2	Ricin (A Subunit), domain 2	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF00161	Ribosome inactivating protein (RIP)	Ribosome inactivating protein	-	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	ALPHA-MOMORCHARIN	hydrolase activity, acting on glycosyl bonds rRNA N-glycosylase activity catalytic activity, acting on RNA catalytic activity, acting on a nucleic acid hydrolase activity catalytic activity, acting on a rRNA catalytic activity RNA glycosylase activity hydrolase activity, hydrolyzing N-glycosyl compounds toxin activity	regulation of cellular process cellular biosynthetic process organonitrogen compound biosynthetic process negative regulation of biological process negative regulation of cellular metabolic process regulation of primary metabolic process post-transcriptional regulation of gene expression negative regulation of translation organic substance metabolic process organic substance biosynthetic process negative regulation of cellular process protein metabolic process negative regulation of protein metabolic process negative regulation of macromolecule metabolic process regulation of cellular process cellular biosynthetic process organonitrogen compound biosynthetic process negative regulation of biological process negative regulation of cellular metabolic process regulation of primary metabolic process post-transcriptional regulation of gene expression negative regulation of translation organic substance metabolic process organic substance biosynthetic process negative regulation of cellular process protein metabolic process negative regulation of protein metabolic process negative regulation of macromolecule metabolic process regulation of biosynthetic process regulation of biological process organonitrogen compound metabolic process cellular metabolic process regulation of protein metabolic process negative regulation of metabolic process biological regulation regulation of cellular metabolic process primary metabolic process regulation of macromolecule metabolic process gene expression translation macromolecule biosynthetic process negative regulation of cellular biosynthetic process regulation of cellular biosynthetic process regulation of gene expression negative regulation of gene expression biosynthetic process negative regulation of biosynthetic process regulation of translation negative regulation of macromolecule biosynthetic process regulation of macromolecule biosynthetic process metabolic process cellular process macromolecule metabolic process regulation of metabolic process response to stimulus defense response response to stress	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR036041	Ribosome-inactivating protein superfamily	Homologous Superfamily
A	IPR017988	Ribosome-inactivating protein conserved site	Conserved Site
A	IPR016139	Ribosome-inactivating protein, subdomain 2	Homologous Superfamily
A	IPR017989	Ribosome-inactivating protein type 1/2	Family
A	IPR016138	Ribosome-inactivating protein, subdomain 1	Homologous Superfamily
A	IPR001574	Ribosome-inactivating protein	Family

Structure Motif Annotation: Mechanism and Catalytic Site Atlas M-CSA Database Homepage

Chains	Enzyme Name	Description	Catalytic Residues
A	rRNA N-glycosylase M-CSA #825	Abrin-A from the seeds of Abrus precatorius is a type II ribosome-inactivating protein (RIP) alongside the homologue Ricin. Like Ricin, it catalyses the endohydrolysis of the N-glycosidic bond at one specific adenosine A4324 on the 28S rRNA. This inhibition of protein biosynthesis is anti-carcinogenic. Abrin-A is composed of two chains which are linked by a disulphide bond. Type I RIPs such as α-Momorcharin however have a single chain, still retaining rRNA-glycosylase activity and share identical catalytic residues to Abrin-A and also excise adenines from a highly conserved loop rRNA.	Defined by 3 residues: ILE:A-71GLU:A-160ARG:A-163 \| Explore in 3D: M-CSA Motif Definition Search M-CSA Motif EC: 3.2.2.22 (PDB Primary Data) Search M-CSA Motif + EC 3.2.2.22

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM133198.