1jx9: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1jx9.gif|left|200px]] | [[Image:1jx9.gif|left|200px]] | ||
'''Penicillin Acylase, mutant''' | {{Structure | ||
|PDB= 1jx9 |SIZE=350|CAPTION= <scene name='initialview01'>1jx9</scene>, resolution 2.28Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=CA:CALCIUM ION'>CA</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Penicillin_amidase Penicillin amidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.1.11 3.5.1.11] | |||
|GENE= PAC ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |||
}} | |||
'''Penicillin Acylase, mutant''' | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
1JX9 is a [ | 1JX9 is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JX9 OCA]. | ||
==Reference== | ==Reference== | ||
Structural and kinetic studies on ligand binding in wild-type and active-site mutants of penicillin acylase., Alkema WB, Hensgens CM, Snijder HJ, Keizer E, Dijkstra BW, Janssen DB, Protein Eng Des Sel. 2004 May;17(5):473-80. Epub 2004 Jul 14. PMID:[http:// | Structural and kinetic studies on ligand binding in wild-type and active-site mutants of penicillin acylase., Alkema WB, Hensgens CM, Snijder HJ, Keizer E, Dijkstra BW, Janssen DB, Protein Eng Des Sel. 2004 May;17(5):473-80. Epub 2004 Jul 14. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15254299 15254299] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Penicillin amidase]] | [[Category: Penicillin amidase]] | ||
| Line 19: | Line 28: | ||
[[Category: Snijder, H J.]] | [[Category: Snijder, H J.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
[[Category: beta- | [[Category: beta-strand]] | ||
[[Category: | [[Category: helice]] | ||
[[Category: ntn-hydrolase fold]] | [[Category: ntn-hydrolase fold]] | ||
''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 12:09:42 2008'' | ||
Revision as of 13:09, 20 March 2008
| |||||||
| , resolution 2.28Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | PAC (Escherichia coli) | ||||||
| Activity: | Penicillin amidase, with EC number 3.5.1.11 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Penicillin Acylase, mutant
OverviewOverview
Penicillin acylase catalyses the condensation of Calpha-substituted phenylacetic acids with beta-lactam nucleophiles, producing semi-synthetic beta-lactam antibiotics. For efficient synthesis a low affinity for phenylacetic acid and a high affinity for Calpha-substituted phenylacetic acid derivatives is desirable. We made three active site mutants, alphaF146Y, betaF24A and alphaF146Y/betaF24A, which all had a 2- to 10-fold higher affinity for Calpha-substituted compounds than wild-type enzyme. In addition, betaF24A had a 20-fold reduced affinity for phenylacetic acid. The molecular basis of the improved properties was investigated by X-ray crystallography. These studies showed that the higher affinity of alphaF146Y for (R)-alpha-methylphenylacetic acid can be explained by van der Waals interactions between alphaY146:OH and the Calpha-substituent. The betaF24A mutation causes an opening of the phenylacetic acid binding site. Only (R)-alpha-methylphenylacetic acid, but not phenylacetic acid, induces a conformation with the ligand tightly bound, explaining the weak binding of phenylacetic acid. A comparison of the betaF24A structure with other open conformations of penicillin acylase showed that betaF24 has a fixed position, whereas alphaF146 acts as a flexible lid on the binding site and reorients its position to achieve optimal substrate binding.
About this StructureAbout this Structure
1JX9 is a Protein complex structure of sequences from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Structural and kinetic studies on ligand binding in wild-type and active-site mutants of penicillin acylase., Alkema WB, Hensgens CM, Snijder HJ, Keizer E, Dijkstra BW, Janssen DB, Protein Eng Des Sel. 2004 May;17(5):473-80. Epub 2004 Jul 14. PMID:15254299
Page seeded by OCA on Thu Mar 20 12:09:42 2008