1nj4: Difference between revisions
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'''Crystal structure of a deacylation-defective mutant of penicillin-binding protein 5 at 1.9 A resolution''' | {{Structure | ||
|PDB= 1nj4 |SIZE=350|CAPTION= <scene name='initialview01'>1nj4</scene>, resolution 1.90Å | |||
|SITE= | |||
|LIGAND= | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Serine-type_D-Ala-D-Ala_carboxypeptidase Serine-type D-Ala-D-Ala carboxypeptidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.16.4 3.4.16.4] | |||
|GENE= DACA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |||
}} | |||
'''Crystal structure of a deacylation-defective mutant of penicillin-binding protein 5 at 1.9 A resolution''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1NJ4 is a [ | 1NJ4 is a [[Single protein]] structure of sequence 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=1NJ4 OCA]. | ||
==Reference== | ==Reference== | ||
Crystal structure of wild-type penicillin-binding protein 5 from Escherichia coli: implications for deacylation of the acyl-enzyme complex., Nicholas RA, Krings S, Tomberg J, Nicola G, Davies C, J Biol Chem. 2003 Dec 26;278(52):52826-33. Epub 2003 Oct 10. PMID:[http:// | Crystal structure of wild-type penicillin-binding protein 5 from Escherichia coli: implications for deacylation of the acyl-enzyme complex., Nicholas RA, Krings S, Tomberg J, Nicola G, Davies C, J Biol Chem. 2003 Dec 26;278(52):52826-33. Epub 2003 Oct 10. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/14555648 14555648] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Serine-type D-Ala-D-Ala carboxypeptidase]] | [[Category: Serine-type D-Ala-D-Ala carboxypeptidase]] | ||
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[[Category: peptidoglycan synthesis]] | [[Category: peptidoglycan synthesis]] | ||
''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 12:57:34 2008'' | ||
Revision as of 13:57, 20 March 2008
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| , resolution 1.90Å | |||||||
|---|---|---|---|---|---|---|---|
| Gene: | DACA (Escherichia coli) | ||||||
| Activity: | Serine-type D-Ala-D-Ala carboxypeptidase, with EC number 3.4.16.4 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of a deacylation-defective mutant of penicillin-binding protein 5 at 1.9 A resolution
OverviewOverview
Penicillin-binding protein 5 (PBP 5) of Escherichia coli functions as a d-alanine carboxypeptidase (CPase), cleaving d-alanine from the C terminus of cell wall peptides. Like all PBPs, PBP 5 forms a covalent acyl-enzyme complex with beta-lactam antibiotics; however, PBP 5 is distinguished by its high rate of deacylation of the acylenzyme complex (t(1/2) approximately 10 min). A Gly105 --> Asp mutation in PBP 5 markedly impairs deacylation with only minor effects on acylation, and abolishes CPase activity. We have determined the three-dimensional structure of a soluble form of wild-type PBP 5 at 1.85-A resolution and have also refined the structure of the G105D mutant form of PBP 5 to 1.9-A resolution. Comparison of the two structures reveals that the major effect of the mutation is to disorder a loop comprising residues 74-90 that sits atop the SXN motif of the active site. Deletion of the 74-90 loop in wild-type PBP 5 markedly diminished the deacylation rate of penicillin G with a minimal impact on acylation, and abolished CPase activity. These effects were very similar to those observed in the G105D mutant, reinforcing the idea that this mutation causes disordering of the 74-90 loop. Mutation of two consecutive serines within this loop, which hydrogen bond to Ser110 and Asn112 in the SXN motif, had marked effects on CPase activity, but not beta-lactam antibiotic binding or hydrolysis. These data suggest a direct role for the SXN motif in deacylation of the acyl-enzyme complex and imply that the functioning of this motif is modulated by the 74-90 loop.
About this StructureAbout this Structure
1NJ4 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of wild-type penicillin-binding protein 5 from Escherichia coli: implications for deacylation of the acyl-enzyme complex., Nicholas RA, Krings S, Tomberg J, Nicola G, Davies C, J Biol Chem. 2003 Dec 26;278(52):52826-33. Epub 2003 Oct 10. PMID:14555648
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