2q3n: Difference between revisions
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'''Agglutinin from Abrus Precatorius (APA-I)''' | {{Structure | ||
|PDB= 2q3n |SIZE=350|CAPTION= <scene name='initialview01'>2q3n</scene>, resolution 3.50Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/rRNA_N-glycosylase rRNA N-glycosylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.22 3.2.2.22] | |||
|GENE= | |||
}} | |||
'''Agglutinin from Abrus Precatorius (APA-I)''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2Q3N is a [ | 2Q3N is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Abrus_precatorius Abrus precatorius]. This structure supersedes the now removed PDB entry 2AMZ. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2Q3N OCA]. | ||
==Reference== | ==Reference== | ||
Structure-function analysis and insights into the reduced toxicity of Abrus precatorius agglutinin I in relation to abrin., Bagaria A, Surendranath K, Ramagopal UA, Ramakumar S, Karande AA, J Biol Chem. 2006 Nov 10;281(45):34465-74. Epub 2006 Jun 13. PMID:[http:// | Structure-function analysis and insights into the reduced toxicity of Abrus precatorius agglutinin I in relation to abrin., Bagaria A, Surendranath K, Ramagopal UA, Ramakumar S, Karande AA, J Biol Chem. 2006 Nov 10;281(45):34465-74. Epub 2006 Jun 13. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16772301 16772301] | ||
[[Category: Abrus precatorius]] | [[Category: Abrus precatorius]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
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[[Category: ribosome-inactivating protein]] | [[Category: ribosome-inactivating protein]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 18:21:13 2008'' | ||
Revision as of 16:21, 20 March 2008
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| 2q3n, resolution 3.50Å | |||||||||||||
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| Ligands: | NAG | ||||||||||||
| Activity: | rRNA N-glycosylase, with EC number 3.2.2.22 | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
Agglutinin from Abrus Precatorius (APA-I)
Overview
Abrin and agglutinin-I from the seeds of Abrus precatorius are type II ribosome-inactivating proteins that inhibit protein synthesis in eukaryotic cells. The two toxins share a high degree of sequence similarity; however, agglutinin-I is weaker in its activity. We compared the kinetics of protein synthesis inhibition by abrin and agglutinin-I in two different cell lines and found that approximately 200-2000-fold higher concentration of agglutinin-I is needed for the same degree of inhibition. Like abrin, agglutinin-I also induced apoptosis in the cells by triggering the intrinsic mitochondrial pathway, although at higher concentrations as compared with abrin. The reason for the decreased toxicity of agglutinin-I became apparent on the analysis of the crystal structure of agglutinin-I obtained by us in comparison with that of the reported structure of abrin. The overall protein folding of agglutinin-I is similar to that of abrin-a with a single disulfide bond holding the toxic A subunit and the lectin-like B-subunit together, constituting a heterodimer. However, there are significant differences in the secondary structural elements, mostly in the A chain. The substitution of Asn-200 in abrin-a with Pro-199 in agglutinin-I seems to be a major cause for the decreased toxicity of agglutinin-I. This perhaps is not a consequence of any kink formation by a proline residue in the helical segment, as reported by others earlier, but due to fewer interactions that proline can possibly have with the bound substrate.
About this Structure
2Q3N is a Protein complex structure of sequences from Abrus precatorius. This structure supersedes the now removed PDB entry 2AMZ. Full crystallographic information is available from OCA.
Reference
Structure-function analysis and insights into the reduced toxicity of Abrus precatorius agglutinin I in relation to abrin., Bagaria A, Surendranath K, Ramagopal UA, Ramakumar S, Karande AA, J Biol Chem. 2006 Nov 10;281(45):34465-74. Epub 2006 Jun 13. PMID:16772301
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