1e25
From Proteopedia
(New page: 200px<br /><applet load="1e25" size="450" color="white" frame="true" align="right" spinBox="true" caption="1e25, resolution 1.90Å" /> '''THE HIGH RESOLUTION ...) |
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| - | [[Image:1e25.gif|left|200px]]<br /><applet load="1e25" size=" | + | [[Image:1e25.gif|left|200px]]<br /><applet load="1e25" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1e25, resolution 1.90Å" /> | caption="1e25, resolution 1.90Å" /> | ||
'''THE HIGH RESOLUTION STRUCTURE OF PER-1 CLASS A BETA-LACTAMASE'''<br /> | '''THE HIGH RESOLUTION STRUCTURE OF PER-1 CLASS A BETA-LACTAMASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The treatment of infectious diseases by beta-lactam antibiotics is | + | The treatment of infectious diseases by beta-lactam antibiotics is continuously challenged by the emergence and dissemination of new beta-lactamases. In most cases, the cephalosporinase activity of class A enzymes results from a few mutations in the TEM and SHV penicillinases. The PER-1 beta-lactamase was characterized as a class A enzyme displaying a cephalosporinase activity. This activity was, however, insensitive to the mutations of residues known to be critical for providing extended substrate profiles to TEM and SHV. The x-ray structure of the protein, solved at 1.9-A resolution, reveals that two of the most conserved features in class A beta-lactamases are not present in this enzyme: the fold of the Omega-loop and the cis conformation of the peptide bond between residues 166 and 167. The new fold of the Omega-loop and the insertion of four residues at the edge of strand S3 generate a broad cavity that may easily accommodate the bulky substituents of cephalosporin substrates. The trans conformation of the 166-167 bond is related to the presence of an aspartic acid at position 136. Selection of class A enzymes based on the occurrence of both Asp(136) and Asn(179) identifies a subgroup of enzymes with high sequence homology. |
==About this Structure== | ==About this Structure== | ||
| - | 1E25 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [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] Full crystallographic information is available from [http:// | + | 1E25 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [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] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1E25 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Pseudomonas aeruginosa]] | [[Category: Pseudomonas aeruginosa]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Bouthors, A | + | [[Category: Bouthors, A T.]] |
[[Category: Guillet, V.]] | [[Category: Guillet, V.]] | ||
[[Category: Maveyraud, L.]] | [[Category: Maveyraud, L.]] | ||
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[[Category: hydrolase]] | [[Category: hydrolase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:23:02 2008'' |
Revision as of 10:23, 21 February 2008
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THE HIGH RESOLUTION STRUCTURE OF PER-1 CLASS A BETA-LACTAMASE
Overview
The treatment of infectious diseases by beta-lactam antibiotics is continuously challenged by the emergence and dissemination of new beta-lactamases. In most cases, the cephalosporinase activity of class A enzymes results from a few mutations in the TEM and SHV penicillinases. The PER-1 beta-lactamase was characterized as a class A enzyme displaying a cephalosporinase activity. This activity was, however, insensitive to the mutations of residues known to be critical for providing extended substrate profiles to TEM and SHV. The x-ray structure of the protein, solved at 1.9-A resolution, reveals that two of the most conserved features in class A beta-lactamases are not present in this enzyme: the fold of the Omega-loop and the cis conformation of the peptide bond between residues 166 and 167. The new fold of the Omega-loop and the insertion of four residues at the edge of strand S3 generate a broad cavity that may easily accommodate the bulky substituents of cephalosporin substrates. The trans conformation of the 166-167 bond is related to the presence of an aspartic acid at position 136. Selection of class A enzymes based on the occurrence of both Asp(136) and Asn(179) identifies a subgroup of enzymes with high sequence homology.
About this Structure
1E25 is a Single protein structure of sequence from Pseudomonas aeruginosa with as ligand. Active as Beta-lactamase, with EC number 3.5.2.6 Full crystallographic information is available from OCA.
Reference
The high resolution crystal structure for class A beta-lactamase PER-1 reveals the bases for its increase in breadth of activity., Tranier S, Bouthors AT, Maveyraud L, Guillet V, Sougakoff W, Samama JP, J Biol Chem. 2000 Sep 8;275(36):28075-82. PMID:10825176
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