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1g68
From Proteopedia
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| - | [[Image:1g68.jpg|left|200px]] | + | [[Image:1g68.jpg|left|200px]] |
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| - | '''PSE-4 CARBENICILLINASE, WILD TYPE''' | + | {{Structure |
| + | |PDB= 1g68 |SIZE=350|CAPTION= <scene name='initialview01'>1g68</scene>, resolution 1.95Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=SO4:SULFATE ION'>SO4</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= PSE4 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=287 Pseudomonas aeruginosa]) | ||
| + | }} | ||
| + | |||
| + | '''PSE-4 CARBENICILLINASE, WILD TYPE''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1G68 is a [ | + | 1G68 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1G68 OCA]. |
==Reference== | ==Reference== | ||
| - | Insights into the molecular basis for the carbenicillinase activity of PSE-4 beta-lactamase from crystallographic and kinetic studies., Lim D, Sanschagrin F, Passmore L, De Castro L, Levesque RC, Strynadka NC, Biochemistry. 2001 Jan 16;40(2):395-402. PMID:[http:// | + | Insights into the molecular basis for the carbenicillinase activity of PSE-4 beta-lactamase from crystallographic and kinetic studies., Lim D, Sanschagrin F, Passmore L, De Castro L, Levesque RC, Strynadka NC, Biochemistry. 2001 Jan 16;40(2):395-402. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11148033 11148033] |
[[Category: Beta-lactamase]] | [[Category: Beta-lactamase]] | ||
[[Category: Pseudomonas aeruginosa]] | [[Category: Pseudomonas aeruginosa]] | ||
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[[Category: class a beta-lactamase]] | [[Category: class a 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 11:18:46 2008'' |
Revision as of 09:18, 20 March 2008
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| , resolution 1.95Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | PSE4 (Pseudomonas aeruginosa) | ||||||
| Activity: | Beta-lactamase, with EC number 3.5.2.6 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
PSE-4 CARBENICILLINASE, WILD TYPE
Overview
PSE-4 is a class A beta-lactamase produced by strains of Pseudomonas aeruginosa and is highly active for the penicillin derivative carbenicillin. The crystal structure of the wild-type PSE-4 carbenicillinase has been determined to 1.95 A resolution by molecular replacement and represents the first structure of a carbenicillinase published to date. A superposition of the PSE-4 structure with that of TEM-1 shows a rms deviation of 1.3 A for 263 Calpha atoms. Most carbenicillinases are unique among class A beta-lactamases in that residue 234 is an arginine (ABL standard numbering scheme), while in all other class A enzymes this residue is a lysine. Kinetic characterization of a R234K PSE-4 mutant reveals a 50-fold reduction in k(cat)/K(m) and confirms the importance of Arg 234 for carbenicillinase activity. A comparison of the structure of the R234K mutant refined to 1.75 A resolution with the wild-type structure shows that Arg 234 stabilizes an alternate conformation of the Ser 130 side chain, not seen in other class A beta-lactamase structures. Our molecular modeling studies suggest that the position of a bound carbenicillin would be shifted relative to that of a bound benzylpenicillin in order to avoid a steric clash between the carbenicillin alpha-carboxylate group and the conserved side chain of Asn 170. The alternate conformation of the catalytic Ser 130 in wild-type PSE-4 may be involved in accommodating this shift in the bound substrate position.
About this Structure
1G68 is a Single protein structure of sequence from Pseudomonas aeruginosa. Full crystallographic information is available from OCA.
Reference
Insights into the molecular basis for the carbenicillinase activity of PSE-4 beta-lactamase from crystallographic and kinetic studies., Lim D, Sanschagrin F, Passmore L, De Castro L, Levesque RC, Strynadka NC, Biochemistry. 2001 Jan 16;40(2):395-402. PMID:11148033
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