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Sequence of the PSE-1 beta-lactamase gene
1Antimicrobial Research Unit, National Public Health Institute, Turku, Finland.
Antimicrobial Agents and Chemotherapy
|November 1, 1991
Summary
The PSE-1 beta-lactamase gene from Tn1403 is within an integron and codes for a class A enzyme. This enzyme shows minor differences from PSE-4 and CARB-3 due to single amino acid changes.
Area of Science:
- Molecular biology
- Genetics
- Enzymology
Background:
- Beta-lactamase enzymes are crucial in antibiotic resistance.
- Integrons are genetic elements that facilitate the acquisition of genes, including those for antibiotic resistance.
- The PSE-1 beta-lactamase is a significant contributor to resistance against beta-lactam antibiotics.
Purpose of the Study:
- To determine the nucleotide sequence of the PSE-1 beta-lactamase gene.
- To investigate the genetic context of the PSE-1 gene, specifically its presence within an integron.
- To analyze the protein sequence and compare it with related beta-lactamases.
Main Methods:
- DNA sequencing of the PSE-1 beta-lactamase gene from the Tn1403 transposon.
- Bioinformatic analysis of the nucleotide and predicted amino acid sequences.
- Comparative analysis with known beta-lactamase sequences, including PSE-4 and CARB-3.
Main Results:
- The PSE-1 beta-lactamase gene is located within an integron on Tn1403.
- The gene encodes a class A beta-lactamase.
- The deduced amino acid sequence of PSE-1 differs from PSE-4 and CARB-3 by single amino acid substitutions.
Conclusions:
- The PSE-1 beta-lactamase gene resides in a mobile genetic element (integron), facilitating its spread.
- The observed amino acid differences suggest potential variations in enzyme activity or substrate specificity compared to PSE-4 and CARB-3.
- Understanding these genetic and protein variations is key to tracking and combating antibiotic resistance.
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