1hzo
From Proteopedia
(New page: 200px<br /><applet load="1hzo" size="450" color="white" frame="true" align="right" spinBox="true" caption="1hzo, resolution 1.75Å" /> '''STRUCTURE OF CLASS A...) |
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| - | [[Image:1hzo.jpg|left|200px]]<br /><applet load="1hzo" size=" | + | [[Image:1hzo.jpg|left|200px]]<br /><applet load="1hzo" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1hzo, resolution 1.75Å" /> | caption="1hzo, resolution 1.75Å" /> | ||
'''STRUCTURE OF CLASS A CEPHALOSPORINASE FROM PROTEUS VULGARIS K1'''<br /> | '''STRUCTURE OF CLASS A CEPHALOSPORINASE FROM PROTEUS VULGARIS K1'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of a chromosomal extended-spectrum beta-lactamase (ESBL) | + | The structure of a chromosomal extended-spectrum beta-lactamase (ESBL) having the ability to hydrolyze cephalosporins including cefuroxime and ceftazidime has been determined by X-ray crystallography to 1.75 A resolution. The species-specific class A beta-lactamase from Proteus vulgaris K1 was crystallized at pH 6.25 and its structure solved by molecular replacement. Refinement of the model resulted in crystallographic R and R(free) of 16.9 % and 19.3 %, respectively. The folding of the K1 enzyme is broadly similar to that of non-ESBL TEM-type beta-lactamases (2 A rmsd for C(alpha)) and differs by only 0.35 A for all atoms of six conserved residues in the catalytic site. Other residues promoting extended-spectrum activity in K1 include the side-chains of atypical residues Ser237 and Lys276. These side-chains are linked by two water molecules, one of which lies in the position normally filled by the guanidinium group of Arg244, present in most non-ESBL enzymes but absent from K1. The ammonium group of Lys276, ca 3.5 A from the virtual Arg244 guanidinium position, may interact with polar R2 substitutents on the dihydrothiazene ring of cephalosporins. |
==About this Structure== | ==About this Structure== | ||
| - | 1HZO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Proteus_vulgaris Proteus vulgaris] with MES 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:// | + | 1HZO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Proteus_vulgaris Proteus vulgaris] with <scene name='pdbligand=MES:'>MES</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=1HZO OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Proteus vulgaris]] | [[Category: Proteus vulgaris]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Crichlow, G | + | [[Category: Crichlow, G V.]] |
| - | [[Category: Knox, J | + | [[Category: Knox, J R.]] |
| - | [[Category: Kuzin, A | + | [[Category: Kuzin, A P.]] |
[[Category: Mayama, K.]] | [[Category: Mayama, K.]] | ||
[[Category: Nukaga, M.]] | [[Category: Nukaga, M.]] | ||
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[[Category: mixed alpha/beta]] | [[Category: mixed alpha/beta]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:06:27 2008'' |
Revision as of 11:06, 21 February 2008
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STRUCTURE OF CLASS A CEPHALOSPORINASE FROM PROTEUS VULGARIS K1
Overview
The structure of a chromosomal extended-spectrum beta-lactamase (ESBL) having the ability to hydrolyze cephalosporins including cefuroxime and ceftazidime has been determined by X-ray crystallography to 1.75 A resolution. The species-specific class A beta-lactamase from Proteus vulgaris K1 was crystallized at pH 6.25 and its structure solved by molecular replacement. Refinement of the model resulted in crystallographic R and R(free) of 16.9 % and 19.3 %, respectively. The folding of the K1 enzyme is broadly similar to that of non-ESBL TEM-type beta-lactamases (2 A rmsd for C(alpha)) and differs by only 0.35 A for all atoms of six conserved residues in the catalytic site. Other residues promoting extended-spectrum activity in K1 include the side-chains of atypical residues Ser237 and Lys276. These side-chains are linked by two water molecules, one of which lies in the position normally filled by the guanidinium group of Arg244, present in most non-ESBL enzymes but absent from K1. The ammonium group of Lys276, ca 3.5 A from the virtual Arg244 guanidinium position, may interact with polar R2 substitutents on the dihydrothiazene ring of cephalosporins.
About this Structure
1HZO is a Single protein structure of sequence from Proteus vulgaris with as ligand. Active as Beta-lactamase, with EC number 3.5.2.6 Full crystallographic information is available from OCA.
Reference
Structure of an extended-spectrum class A beta-lactamase from Proteus vulgaris K1., Nukaga M, Mayama K, Crichlow GV, Knox JR, J Mol Biol. 2002 Mar 15;317(1):109-17. PMID:11916382
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