PloS one, 2016-02, Vol.11 (2), p.e0149145-e0149145
2016
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Details
- Autor(en) / Beteiligte
- Titel
- Involvement of a Novel Class C Beta-Lactamase in the Transglutaminase Mediated Cross-Linking Cascade of Streptomyces mobaraensis DSM 40847
- Ist Teil von
- PloS one, 2016-02, Vol.11 (2), p.e0149145-e0149145
- Ort / Verlag
- United States: Public Library of Science
- Erscheinungsjahr
- 2016
- Quelle
- MEDLINE
- Beschreibungen/Notizen
- Streptomyces mobaraensis DSM 40847 secretes transglutaminase that cross-links proteins via γ-glutamyl-ε-lysine isopeptide bonds. Characterized substrates are inhibitory proteins acting against various serine, cysteine and metalloproteases. In the present study, the bacterial secretome was examined to uncover additional transglutaminase substrates. Fractional ethanol precipitation of the exported proteins at various times of culture growth, electrophoresis of the precipitated proteins, and sequencing of a 39 kDa protein by mass spectrometry revealed the novel beta-lactamase Sml-1. As indicated by biotinylated probes, Sml-1, produced in E. coli, exhibits glutamine and lysine residues accessible for transglutaminase. The chromogenic cephalosporin analogue, nitrocefin, was hydrolyzed by Sml-1 with low velocity. The obtained Km and kcat values of the recombinant enzyme were 94.3±1.8 μM and 0.39±0.03 s(-1), respectively. Penicillin G and ampicillin proved to be weak inhibitors of nitrocefin hydrolysis (Ki of 0.1 mM and 0.18 mM). Negligible influence of metals on β-lactamase activity ruled out that Sml-1 is a Zn2+-dependent class B beta-lactamase. Rather, sequence motifs such as SITK, YSN, and HDG forming the active core in a hypothetical structure may be typical for class C beta-lactamases. Based on the results, we assume that the novel transglutaminase substrate ensures undisturbed growth of aerial hyphae in Streptomyces mobaraensis by trapping and inactivating hostile beta-lactam antibiotics.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 1932-6203eISSN: 1932-6203DOI: 10.1371/journal.pone.0149145Titel-ID: cdi_plos_journals_1765913382
- Format
- –
- Schlagworte
- Amides, Amino Acid Motifs, Amino Acid Sequence, Ampicillin, Antibiotics, Bacteria, Bacterial Proteins - chemistry, Bacterial Proteins - metabolism, Beta lactamases, beta-Lactamases - chemistry, beta-Lactamases - metabolism, Binding sites, Biology, Biology and Life Sciences, Biotechnology, Biotinylation, Catalytic Domain, Cephalosporins, Chemical engineering, Cross-Linking Reagents - metabolism, Crosslinking, E coli, Enzymes, Escherichia coli - metabolism, Ethanol, Extracellular Space - metabolism, Gene expression, Genes, Genetic aspects, Glutamine, Hyphae, Identification and classification, Kinetics, Lysine, Mass spectrometry, Mass spectroscopy, Medicine and Health Sciences, Metals, Models, Molecular, Molecular Sequence Data, Molecular Weight, Observations, Penicillin, Physical Sciences, Proteins, Recombinant Proteins - biosynthesis, Research and Analysis Methods, Secretome, Serine, Streptomyces, Streptomyces - enzymology, Substrate inhibition, Substrate Specificity, Substrates, Transglutaminases - metabolism, Zinc, β Lactamase, β-Lactam antibiotics