Sequence of PSE-2 beta-lactamase

Huovinen, Pentti; Huovinen, Saara; Jacoby, George A.

doi:10.1128/aac.32.1.134

Cited by 150 publications

(89 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Sequence analysis has shown that the larger probe contains 101 base pairs external to the PSE-2 gene that are 100% identical to the sequence proximal to the OXA-2 bla gene (7). Three of five strains falsely reacting with the 1.2-kb PSE-2 probe made (15,25) and has considerable amino acid sequence similarity with the OXA-2 enzyme (7).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Detection of plasmid-mediated beta-lactamases with DNA probes

Huovinen

Jacoby

1988

Antimicrob Agents Chemother

Self Cite

View full text Add to dashboard Cite

P-Lactamase identffication by colony hybridization with 32P-labeled DNA probes for TEM-1, SHV-1, OXA-1, OXA-2, PSE-1, PSE-2, and PSE-4 was compared with isoelectric focusing in 122 clinical isolates making a variety of enzyme types. All strains producing a probe-type enzyme gave a positive hybridization reaction. Cross-hybridization was observed between TEM-1 and TEM-2 or TLE-1, between SHV-1 and SHV-2, between OXA-1 and OXA-4, between OXA-2 and OXA-3 (weak), between PSE-2 and OXA-6 or OXA-5 (weak), and among PSE-1, PSE-4, and CARB-3. With allowance for such cross-hybridization, only six strains gave false-positive reactions, and the procedure was 99% specific.Biochemical studies have established that plasmids in gram-negative bacteria determine a variety of P-lactamase types. The enzymes can be differentiated by substrate profile, reactions with inhibitors, molecular weight, and particularly isoelectric point (pl) into at least 25 kinds (16,19,32). Some, such as TEM-1 and SHV-1, have broad-spectrum but relatively unspecialized activity. As their name implies, the OXA set hydrolyzes oxacillin and related P-lactams with particular efficiency, whereas CARB enzymes, also given PSE designations because they were first found in Pseudomonas aeruginosa, are notably effective in carbenicillin hydrolysis. Distinguishing between the enzymes is of value for epidemiological studies where the presence of a less common P-lactamase type may allow a particular strain or plasmid to be traced (20). The distribution of P-lactamase types in different organisms may also help elucidate where these enzymes originated and how they have spread in response to the use and elaboration of P-lactam antibiotics.Studies relying on isoelectric focusing have demonstrated TEM-1 as the predominant P-lactamase in ampicillin-resistant Escherichia coli and Salmonella spp., whereas SHV-1 is preponderant in Klebsiella spp. (29). In P. aeruginosa carbenicillin or ticarcillin resistance due to ,-lactamase production is the result mainly of PSE-1 or PSE-4 (24, 33).If P-lactamase genes are as diverse as the enzymes they encode, it should be possible to develop DNA probes for P-lactamase identification that would allow more rapid studies with large numbers of strains. DNA fragments suitable as probes for TEM-1 (3, 12, 22), OXA-1 (12, 23), OXA-2 (2), and PSE-1 (12) have been described and have been studied for specificity by utilizing purified plasmid DNA. The purpose of this investigation was to apply such probes to clinical isolates to evaluate their sensitivity and specificity. MATERIALS AND METHODSBacterial strains. strains were demonstrated to grow on plates containing 25 ,ug of ampicillin per ml and to produce ,-lactamase as determined by the nitrocefin test (21). Because no probetype P-lactamases were detected among P. aeruginosa isolates from this source, 20 P. aeruginosa clinical isolates with known plasmid-mediated P-lactamases collected by A. Philippon in France before 1981 were also included in hybridization studies.Analytical isoelectric focusin...

show abstract

Section: Discussionmentioning

confidence: 99%

“…Probes for TEM-1 and OXA-2 are intragenic (4,31). An intragenic probe was also developed for the PSE-2 bla gene based on the recent determination of its DNA sequence (7).…”

Section: Methodsmentioning

confidence: 99%

Detection of plasmid-mediated beta-lactamases with DNA probes

Huovinen

Jacoby

1988

Antimicrob Agents Chemother

Self Cite

View full text Add to dashboard Cite

show abstract

“…b-Lactamases can be divided into four classes based on amino acid sequence homologies. [1][2][3] The class B enzymes are zincdependent metallo-b-lactamases that are structurally and mechanistically independent of the other three classes of active-site serine b-lactamases (A, C, and D). Homology searches combined with multiple sequence alignments have identified several common structural elements between active-site serine b-lactamases and PBPs.…”

mentioning

confidence: 99%

Analysis of the plasticity of location of the Arg244 positive charge within the active site of the TEM‐1 β‐lactamase

2009

View full text Add to dashboard Cite

A large number of b-lactamases have emerged that are capable of conferring bacterial resistance to b-lactam antibiotics. Comparison of the structural and functional features of this family has refined understanding of the catalytic properties of these enzymes. An arginine residue present at position 244 in TEM-1 b-lactamase interacts with the carboxyl group common to penicillin and cephalosporin antibiotics and thereby stabilizes both the substrate and transition state complexes. A comparison of class A b-lactamase sequences reveals that arginine at position 244 is not conserved, although a positive charge at this structural location is conserved and is provided by an arginine at positions 220 or 276 for those enzymes lacking arginine at position 244. The plasticity of the location of positive charge in the b-lactamase active site was experimentally investigated by relocating the arginine at position 244 in TEM-1 b-lactamase to positions 220, 272, and 276 by site-directed mutagenesis. Kinetic analysis of the engineered b-lactamases revealed that removal of arginine 244 by alanine mutation reduced catalytic efficiency against all substrates tested and restoration of an arginine at positions 272 or 276 partially suppresses the catalytic defect of the Arg244Ala substitution. These results suggest an evolutionary mechanism for the observed divergence of the position of positive charge in the active site of class A b-lactamases.

show abstract

“…similar structure is consistent with its status as a lessevolved integron. The presence of such an element has been reported to be required on at least one of the sequences participating in the Int-mediated crossing over at the GTT sequence at crossover point 1 (28 (46), aacAlb (8), aadAl (49), aadA2 (36,38,53), aadB (43), dhfrII (52,62), dhfrV (49), oxa2 (19), aacAla (56), aacCl (61), cmUA (3), dhfrI (51), oxal (32), pse2 (20), pse4 (7), and merA (9) were from the respective references.…”

mentioning

confidence: 99%

Characterization of In0 of Pseudomonas aeruginosa plasmid pVS1, an ancestor of integrons of multiresistance plasmids and transposons of gram-negative bacteria

1992

View full text Add to dashboard Cite

Many multiresistance plasmids and transposons of gram-negative bacteria carry related DNA elements that appear to have evolved from a common ancestor by site-specific integration of discrete cassettes containing antibiotic resistance genes or sequences of unknown function. The site of integration is flanked by conserved segments coding for an integraselike protein and for sulfonamide resistance, respectively. These segments, together with the antibiotic resistance genes between them, have been termed integrons (H. W. Stokes and R. M. Hall, Mol. Microbiol. 3:1669-1683. We report here the characterization of an integron, InO, from Pseudomonas aeruginosa plasmid pVSI, which has an unoccupied integration site and hence may be an ancestor of more complex integrons. Codon usage of the integrase (int) and sulfonamide resistance (sull) genes carried by this integron suggests a common origin. This contrasts with the codon usage of other antibiotic resistance genes that were presumably integrated later as cassettes during the evolution and spread of these DNA elements. We propose evolutionary schemes for (i) the genesis of the integrons by the site-specific integration of antibiotic resistance genes and (ii) the evolution of the integrons of multiresistance plasmids and transposons, in relation to the evolution of transposons related to Tn2l.

show abstract

Sequence of PSE-2 beta-lactamase

Cited by 150 publications

References 17 publications

Detection of plasmid-mediated beta-lactamases with DNA probes

Detection of plasmid-mediated beta-lactamases with DNA probes

Analysis of the plasticity of location of the Arg244 positive charge within the active site of the TEM‐1 β‐lactamase

Characterization of In0 of Pseudomonas aeruginosa plasmid pVS1, an ancestor of integrons of multiresistance plasmids and transposons of gram-negative bacteria

Contact Info

Product

Resources

About