1fqg
From Proteopedia
(New page: 200px<br /><applet load="1fqg" size="450" color="white" frame="true" align="right" spinBox="true" caption="1fqg, resolution 1.7Å" /> '''MOLECULAR STRUCTURE O...) |
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| - | [[Image:1fqg.jpg|left|200px]]<br /><applet load="1fqg" size=" | + | [[Image:1fqg.jpg|left|200px]]<br /><applet load="1fqg" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1fqg, resolution 1.7Å" /> | caption="1fqg, resolution 1.7Å" /> | ||
'''MOLECULAR STRUCTURE OF THE ACYL-ENZYME INTERMEDIATE IN TEM-1 BETA-LACTAMASE'''<br /> | '''MOLECULAR STRUCTURE OF THE ACYL-ENZYME INTERMEDIATE IN TEM-1 BETA-LACTAMASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The X-ray crystal structure of the molecular complex of penicillin G with | + | The X-ray crystal structure of the molecular complex of penicillin G with a deacylation-defective mutant of the RTEM-1 beta-lactamase from Escherichia coli shows how these antibiotics are recognized and destroyed. Penicillin G is covalently bound to Ser 70 0 gamma as an acyl-enzyme intermediate. The deduced catalytic mechanism uses Ser 70 0 gamma as the attacking nucleophile during acylation. Lys 73 N zeta acts as a general base in abstracting a proton from Ser 70 and transferring it to the thiazolidine ring nitrogen atom via Ser 130 0 gamma. Deacylation is accomplished by nucleophilic attack on the penicilloyl carbonyl carbon by a water molecule assisted by the general base, Glu 166. |
==About this Structure== | ==About this Structure== | ||
| - | 1FQG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with PNM 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:// | + | 1FQG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=PNM:'>PNM</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=1FQG OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Strynadka, N | + | [[Category: Strynadka, N C.]] |
[[Category: PNM]] | [[Category: PNM]] | ||
[[Category: acyl-enzyme]] | [[Category: acyl-enzyme]] | ||
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[[Category: penicillin]] | [[Category: penicillin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:41:34 2008'' |
Revision as of 10:41, 21 February 2008
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MOLECULAR STRUCTURE OF THE ACYL-ENZYME INTERMEDIATE IN TEM-1 BETA-LACTAMASE
Overview
The X-ray crystal structure of the molecular complex of penicillin G with a deacylation-defective mutant of the RTEM-1 beta-lactamase from Escherichia coli shows how these antibiotics are recognized and destroyed. Penicillin G is covalently bound to Ser 70 0 gamma as an acyl-enzyme intermediate. The deduced catalytic mechanism uses Ser 70 0 gamma as the attacking nucleophile during acylation. Lys 73 N zeta acts as a general base in abstracting a proton from Ser 70 and transferring it to the thiazolidine ring nitrogen atom via Ser 130 0 gamma. Deacylation is accomplished by nucleophilic attack on the penicilloyl carbonyl carbon by a water molecule assisted by the general base, Glu 166.
About this Structure
1FQG is a Single protein structure of sequence from Escherichia coli with as ligand. Active as Beta-lactamase, with EC number 3.5.2.6 Full crystallographic information is available from OCA.
Reference
Molecular structure of the acyl-enzyme intermediate in beta-lactam hydrolysis at 1.7 A resolution., Strynadka NC, Adachi H, Jensen SE, Johns K, Sielecki A, Betzel C, Sutoh K, James MN, Nature. 1992 Oct 22;359(6397):700-5. PMID:1436034
Page seeded by OCA on Thu Feb 21 12:41:34 2008
