Structure of an extended-spectrum class A β-lactamase from Proteus vulgaris K1

Nukaga, Michiyoshi; Mayama, Kayoko; Knox, James R.

doi:10.1006/jmbi.2002.5420

Cited by 19 publications

(18 citation statements)

References 43 publications

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“…This positively charged site plays a role in binding the carboxylate group of -lactamase substrates, including imipenem in TEM-1 (Wang et al, 2002), penicillin G in TEM-1 (Strynadka et al, 1992) and benzylpenicillin, cephaloridine and clavulanic acid in Staphylococcus aureus -lactamase PC1 (Chen & Herzberg, 1992). Moreover, a sulfate anion is observed in an almost identical position in other class A -lactamases, including TEM-1 (Jelsch et al, 1993) and PER-1 (Tranier et al, 2000), and this site also binds the carboxylate group of bicine in KPC-2 (Ke et al, 2007) and the sulfonate moiety of MES buffer in the ESBL from P. vulgaris K-1 (Nukaga et al, 2002). The presence of the sulfate anion in GES-1 was somewhat surprising, given that at no stage during protein purification were any buffers used that contained sulfate.…”

Section: Figurementioning

confidence: 99%

Structure of GES-1 at atomic resolution: insights into the evolution of carbapenamase activity in the class A extended-spectrum β-lactamases

Smith

Caccamo

Kantardjieff

et al. 2007

Acta Crystallogr D Biol Cryst

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The structure of the class A extended-spectrum beta-lactamase GES-1 from Klebsiella pneumoniae has been determined to 1.1 A resolution. GES-1 has the characteristic active-site disulfide bond of the carbapenemase family of beta-lactamases and has a structure that is very similar to those of other known carbapenemases, including NMC-A, SME-1 and KPC-2. Most residues implicated in the catalytic mechanism of this class of enzyme are present in the GES-1 active site, including Ser70, which forms a covalent bond with the carbonyl C atom of the beta-lactam ring of the substrate during the formation of an acyl-enzyme intermediate, Glu166, which is implicated as both the acylation and deacylation base, and Lys73, which is also implicated as the acylation base. A water molecule crucial to catalysis is observed in an identical location as in other class A beta-lactamases, interacting with the side chains of Ser70 and Glu166. One important residue, Asn170, also normally a ligand for the hydrolytic water, is missing from the GES-1 active site. This residue is a glycine in GES-1 and the enzyme is unable to hydrolyze imipenem. This points to this residue as being critically important in the hydrolysis of this class of beta-lactam substrate. This is further supported by flexible-docking studies of imipenem with in silico-generated Gly170Asn and Gly170Ser mutant GES-1 enzymes designed to mimic the active sites of imipenem-hydrolyzing point mutants GES-2 and GES-5.

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Section: Figurementioning

confidence: 99%

Structure of GES-1 at atomic resolution: insights into the evolution of carbapenamase activity in the class A extended-spectrum β-lactamases

Smith

Caccamo

Kantardjieff

et al. 2007

Acta Crystallogr D Biol Cryst

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“…2 The hydrolytic process mediated by these enzymes has been widely documented notably in studies of β-lactamases. [3][4][5][6][7][8][9][10][11][12] They act via a covalent intermediate. 13 In β-lactamases, the acyl-enzyme intermediate is formed between the β-lactam moiety and the conserved active-site serine residue.…”

Section: Introductionmentioning

confidence: 99%

Structural Insights into Substrate Recognition and Product Expulsion in CTX-M Enzymes

Delmas

Leyssene

Dubois

et al. 2010

Journal of Molecular Biology

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“…WAT 65 is part of a hydrogen bond network with the side chain oxygen of Ser 70 , as well as the side chain oxygen of Glu 166 , both at a distance of 2.5 Å. This hydrolytic water functions to deacylate Ser 70 from the product after hydrolysis of ␤-lactam substrates (21,31,40). WAT 36 is in the oxyanion hole, forming hydrogen bonds with the backbone nitrogen of Ser 70 and the backbone nitrogen of Thr 237 at distances of 2.6 Å and 2.7 Å, respectively.…”

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confidence: 99%

Crystal Structure and Activity Studies of the Mycobacterium tuberculosis β-Lactamase Reveal Its Critical Role in Resistance to β-Lactam Antibiotics

Wang

Cassidy

Sacchettini

2006

Antimicrob Agents Chemother

144

216

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␤-Lactam antibiotics are extremely effective in disrupting the synthesis of the bacterial cell wall in both gram-positive and gram-negative bacteria. However, they are ineffective against Mycobacterium tuberculosis, due to the production of a ␤-lactamase enzyme encoded on the chromosome of M. tuberculosis that degrades these antibiotics. Indeed, recent studies have demonstrated that deletion of the blaC gene, the only gene encoding a ␤-lactamase in M. tuberculosis, or inhibition of the encoded enzyme resulted in significantly increased sensitivity to ␤-lactam antibiotics. In this paper we present a biochemical and structural characterization of M. tuberculosis BlaC. Recombinant BlaC shows a broad range of specificity with almost equal penicillinase and cepholothinase activity. While clavulanate is a mechanism-based inhibitor to class A ␤-lactamase with high potency (typically K i < 0.1 M), it is a relatively poor inhibitor of the M. tuberculosis BlaC (K i ‫؍‬ 2.4 M). The crystal structure of the enzyme, determined at a resolution of 1.7 Å, shows that the overall fold of the M. tuberculosis enzyme is similar to other class A ␤-lactamases. There are, however, several distinct features of the active site, such as the amino acid substitutions N132G, R164A, R244A, and R276E, that explain the broad specificity of the enzyme, relatively low penicillinase activity, and resistance to clavulanate.

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Structure of an extended-spectrum class A β-lactamase from Proteus vulgaris K1

Cited by 19 publications

References 43 publications

Structure of GES-1 at atomic resolution: insights into the evolution of carbapenamase activity in the class A extended-spectrum β-lactamases

Structure of GES-1 at atomic resolution: insights into the evolution of carbapenamase activity in the class A extended-spectrum β-lactamases

Structural Insights into Substrate Recognition and Product Expulsion in CTX-M Enzymes

Crystal Structure and Activity Studies of the Mycobacterium tuberculosis β-Lactamase Reveal Its Critical Role in Resistance to β-Lactam Antibiotics

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