1i2w: Difference between revisions
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'''BETA-LACTAMASE FROM BACILLUS LICHENIFORMIS BS3 COMPLEXED WITH CEFOXITIN''' | {{Structure | ||
|PDB= 1i2w |SIZE=350|CAPTION= <scene name='initialview01'>1i2w</scene>, resolution 1.70Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=CFX:CEFOXITIN'>CFX</scene> and <scene name='pdbligand=OUT:CARBAMIC ACID'>OUT</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Beta-lactamase Beta-lactamase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.2.6 3.5.2.6] | |||
|GENE= | |||
}} | |||
'''BETA-LACTAMASE FROM BACILLUS LICHENIFORMIS BS3 COMPLEXED WITH CEFOXITIN''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1I2W is a [ | 1I2W is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I2W OCA]. | ||
==Reference== | ==Reference== | ||
Crystal structures of the Bacillus licheniformis BS3 class A beta-lactamase and of the acyl-enzyme adduct formed with cefoxitin., Fonze E, Vanhove M, Dive G, Sauvage E, Frere JM, Charlier P, Biochemistry. 2002 Feb 12;41(6):1877-85. PMID:[http:// | Crystal structures of the Bacillus licheniformis BS3 class A beta-lactamase and of the acyl-enzyme adduct formed with cefoxitin., Fonze E, Vanhove M, Dive G, Sauvage E, Frere JM, Charlier P, Biochemistry. 2002 Feb 12;41(6):1877-85. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11827533 11827533] | ||
[[Category: Bacillus licheniformis]] | [[Category: Bacillus licheniformis]] | ||
[[Category: Beta-lactamase]] | [[Category: Beta-lactamase]] | ||
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[[Category: serine beta-lactamase]] | [[Category: serine beta-lactamase]] | ||
''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 11:44:51 2008'' | ||
Revision as of 09:44, 20 March 2008
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| 1i2w, resolution 1.70Å | |||||||||||||
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| Ligands: | CFX and OUT | ||||||||||||
| Activity: | Beta-lactamase, with EC number 3.5.2.6 | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
BETA-LACTAMASE FROM BACILLUS LICHENIFORMIS BS3 COMPLEXED WITH CEFOXITIN
Overview
The Bacillus licheniformis BS3 beta-lactamase catalyzes the hydrolysis of the beta-lactam ring of penicillins, cephalosporins, and related compounds. The production of beta-lactamases is the most common and thoroughly studied cause of antibiotic resistance. Although they escape the hydrolytic activity of the prototypical Staphylococcus aureus beta-lactamase, many cephems are good substrates for a large number of beta-lactamases. However, the introduction of a 7alpha-methoxy substituent, as in cefoxitin, extends their antibacterial spectrum to many cephalosporin-resistant Gram-negative bacteria. The 7alpha-methoxy group selectively reduces the hydrolytic action of many beta-lactamases without having a significant effect on the affinity for the target enzymes, the membrane penicillin-binding proteins. We report here the crystallographic structures of the BS3 enzyme and its acyl-enzyme adduct with cefoxitin at 1.7 A resolution. The comparison of the two structures reveals a covalent acyl-enzyme adduct with perturbed active site geometry, involving a different conformation of the omega-loop that bears the essential catalytic Glu166 residue. This deformation is induced by the cefoxitin side chain whose position is constrained by the presence of the alpha-methoxy group. The hydrolytic water molecule is also removed from the active site by the 7beta-carbonyl of the acyl intermediate. In light of the interactions and steric hindrances in the active site of the structure of the BS3-cefoxitin acyl-enzyme adduct, the crucial role of the conserved Asn132 residue is confirmed and a better understanding of the kinetic results emerges.
About this Structure
1I2W is a Single protein structure of sequence from Bacillus licheniformis. Full crystallographic information is available from OCA.
Reference
Crystal structures of the Bacillus licheniformis BS3 class A beta-lactamase and of the acyl-enzyme adduct formed with cefoxitin., Fonze E, Vanhove M, Dive G, Sauvage E, Frere JM, Charlier P, Biochemistry. 2002 Feb 12;41(6):1877-85. PMID:11827533
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