2v2f: Difference between revisions

Revision as of 19:52, 21 February 2008

CRYSTAL STRUCTURE OF PBP1A FROM DRUG-RESISTANT STRAIN 5204 FROM STREPTOCOCCUS PNEUMONIAE

OverviewOverview

The development of high level beta-lactam resistance in the pneumococcus requires the expression of an altered form of PBP1a, in addition to modified forms of PBP2b and PBP2x, which are necessary for the appearance of low levels of resistance. Here, we present the crystal structure of a soluble form of PBP1a from the highly resistant Streptococcus pneumoniae strain 5204 (minimal inhibitory concentration of cefotaxime is 12 mg.liter(-1)). Mutations T371A, which is adjacent to the catalytic nucleophile Ser(370), and TSQF(574-577)NTGY, which lie in a loop bordering the active site cleft, were investigated by site-directed mutagenesis. The consequences of these substitutions on reaction kinetics with beta-lactams were probed in vitro, and their effect on resistance was measured in vivo. The results are interpreted in the framework of the crystal structure, which displays a narrower, discontinuous active site cavity, compared with that of PBP1a from the beta-lactam susceptible strain R6, as well as a reorientation of the catalytic Ser(370).

About this StructureAbout this Structure

2V2F is a Single protein structure of sequence from Streptococcus pneumoniae with and as ligands. Active as Peptidoglycan glycosyltransferase, with EC number 2.4.1.129 Known structural/functional Sites: and . Full crystallographic information is available from OCA.

ReferenceReference

Common Alterations in PBP1a from Resistant Streptococcus pneumoniae Decrease Its Reactivity toward {beta}-Lactams: STRUCTURAL INSIGHTS., Job V, Carapito R, Vernet T, Dessen A, Zapun A, J Biol Chem. 2008 Feb 22;283(8):4886-94. Epub 2007 Nov 30. PMID:18055459

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 ==Overview==
-The development of high level beta-lactam resistance in the pneumococcus, requires the expression of an altered form of PBP1a, in addition to, modified forms of PBP2b and PBP2x, which are necessary for the appearance, of low levels of resistance. Here, we present the crystal structure of a, soluble form of PBP1a from the highly resistant S. pneumoniae strain 5204, (minimal inhibitory concentration of cefotaxime = 12 mg.L(-1)). Mutations, T371A, which is adjacent to the catalytic nuclophile Ser370, and, TSQF(574-577)NTGY, which lie in a loop bordering the active site cleft, were investigated by site-directed mutagenesis. The consequences of these, substitutions on reaction kinetics with beta-lactams were probed in vitro, and their effect on resistance were measured in vivo. The results are, interpreted in the framework of the crystal structure, which displays a, narrower, discontinuous active site cavity, compared to that of PBP1a from, the beta-lactam susceptible strain R6, as well as a reorientation of the, catalytic Ser370.
+The development of high level beta-lactam resistance in the pneumococcus requires the expression of an altered form of PBP1a, in addition to modified forms of PBP2b and PBP2x, which are necessary for the appearance of low levels of resistance. Here, we present the crystal structure of a soluble form of PBP1a from the highly resistant Streptococcus pneumoniae strain 5204 (minimal inhibitory concentration of cefotaxime is 12 mg.liter(-1)). Mutations T371A, which is adjacent to the catalytic nucleophile Ser(370), and TSQF(574-577)NTGY, which lie in a loop bordering the active site cleft, were investigated by site-directed mutagenesis. The consequences of these substitutions on reaction kinetics with beta-lactams were probed in vitro, and their effect on resistance was measured in vivo. The results are interpreted in the framework of the crystal structure, which displays a narrower, discontinuous active site cavity, compared with that of PBP1a from the beta-lactam susceptible strain R6, as well as a reorientation of the catalytic Ser(370).
 ==About this Structure==
-V2F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus_pneumoniae Streptococcus pneumoniae] with <scene name='pdbligand=BA:'>BA</scene> and <scene name='pdbligand=MES:'>MES</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Peptidoglycan_glycosyltransferase Peptidoglycan glycosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.129 2.4.1.129] Known structural/functional Sites: <scene name='pdbsite=AC1:Ba Binding Site For Chain F'>AC1</scene> and <scene name='pdbsite=AC2:Mes Binding Site For Chain F'>AC2</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2V2F OCA].
+V2F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus_pneumoniae Streptococcus pneumoniae] with <scene name='pdbligand=BA:'>BA</scene> and <scene name='pdbligand=MES:'>MES</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Peptidoglycan_glycosyltransferase Peptidoglycan glycosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.129 2.4.1.129] Known structural/functional Sites: <scene name='pdbsite=AC1:Ba+Binding+Site+For+Chain+F'>AC1</scene> and <scene name='pdbsite=AC2:Mes+Binding+Site+For+Chain+F'>AC2</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2V2F OCA].
 ==Reference==
-Common alterations in PBP1a from resistant streptococcus pneumoniae decrease its reactivity towards beta -lactams: Structural insights., Job V, Carapito R, Vernet T, Dessen A, Zapun A, J Biol Chem. 2007 Nov 30;. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=18055459 18055459]
+Common Alterations in PBP1a from Resistant Streptococcus pneumoniae Decrease Its Reactivity toward {beta}-Lactams: STRUCTURAL INSIGHTS., Job V, Carapito R, Vernet T, Dessen A, Zapun A, J Biol Chem. 2008 Feb 22;283(8):4886-94. Epub 2007 Nov 30. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=18055459 18055459]
 [[Category: Peptidoglycan glycosyltransferase]]
 [[Category: Single protein]]
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 [[Category: transpeptidase activity]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 11:28:19 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:52:44 2008''