1uq4
From Proteopedia
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| - | [[Image:1uq4.jpg|left|200px]] | + | [[Image:1uq4.jpg|left|200px]] |
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| - | '''RICIN A-CHAIN (RECOMBINANT) R213D MUTANT''' | + | {{Structure |
| + | |PDB= 1uq4 |SIZE=350|CAPTION= <scene name='initialview01'>1uq4</scene>, resolution 1.9Å | ||
| + | |SITE= <scene name='pdbsite=AC1:So4+Binding+Site+For+Chain+A'>AC1</scene> | ||
| + | |LIGAND= <scene name='pdbligand=SO4:SULFATE ION'>SO4</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= | ||
| + | }} | ||
| + | |||
| + | '''RICIN A-CHAIN (RECOMBINANT) R213D MUTANT''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1UQ4 is a [ | + | 1UQ4 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Ricinus_communis Ricinus communis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UQ4 OCA]. |
==Reference== | ==Reference== | ||
| - | The effect of mutations surrounding and within the active site on the catalytic activity of ricin A chain., Marsden CJ, Fulop V, Day PJ, Lord JM, Eur J Biochem. 2004 Jan;271(1):153-62. PMID:[http:// | + | The effect of mutations surrounding and within the active site on the catalytic activity of ricin A chain., Marsden CJ, Fulop V, Day PJ, Lord JM, Eur J Biochem. 2004 Jan;271(1):153-62. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/14686928 14686928] |
[[Category: Ricinus communis]] | [[Category: Ricinus communis]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: toxin]] | [[Category: toxin]] | ||
| - | ''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 14:35:20 2008'' |
Revision as of 12:35, 20 March 2008
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| , resolution 1.9Å | |||||||
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| Sites: | |||||||
| Ligands: | |||||||
| Activity: | rRNA N-glycosylase, with EC number 3.2.2.22 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
RICIN A-CHAIN (RECOMBINANT) R213D MUTANT
Overview
Models for the binding of the sarcin-ricin loop (SRL) of 28S ribosomal RNA to ricin A chain (RTA) suggest that several surface exposed arginine residues surrounding the active site cleft make important interactions with the RNA substrate. The data presented in this study suggest differing roles for these arginyl residues. Substitution of Arg48 or Arg213 with Ala lowered the activity of RTA 10-fold. Furthermore, substitution of Arg213 with Asp lowered the activity of RTA 100-fold. The crystal structure of this RTA variant showed it to have an unaltered tertiary structure, suggesting that the positively charged state of Arg213 is crucial for activity. Substitution of Arg258 with Ala had no effect on activity, although substitution with Asp lowered activity 10-fold. Substitution of Arg134 prevented expression of folded protein, suggesting a structural role for this residue. Several models have been proposed for the binding of the SRL to the active site of RTA in which the principal difference lies in the conformation of the second 'G' in the target GAGA motif in the 28S rRNA substrate. In one model, the sidechain of Asn122 is proposed to make interactions with this G, whereas another model proposes interactions with Asp75 and Asn78. Site-directed mutagenesis of these residues of RTA favours the first of these models, as substitution of Asn78 with Ser yielded an RTA variant whose activity was essentially wild-type, whereas substitution of Asn122 reduced activity 37.5-fold. Substitution of Asp75 failed to yield significant folded protein, suggesting a structural role for this residue.
About this Structure
1UQ4 is a Single protein structure of sequence from Ricinus communis. Full crystallographic information is available from OCA.
Reference
The effect of mutations surrounding and within the active site on the catalytic activity of ricin A chain., Marsden CJ, Fulop V, Day PJ, Lord JM, Eur J Biochem. 2004 Jan;271(1):153-62. PMID:14686928
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