Cloning, sequencing and expression in Escherichia coli of the low-affinity penicillin binding protein of Enterococcus faecalis |
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Authors: | C. Signoretto M. Boaretti P. Canepari |
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Affiliation: | Istituto di Microbiologia, Universitádi Verona, Strada Le Grazie, 37134 Verona, Italy |
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Abstract: | Abstract Low-affinity penicillin binding proteins are particular membrane proteins, in several Gram-positive bacteria, which are involved in β-lactam antibiotic resistance. The structural gene for the low-affinity penicillin binding protein 5 (PBP5) of Enterococcus faecalis was cloned and sequenced. From the sequence of the 3378 bp, a 2040 bp coding region was identified. From biochemical analysis it emerges that E. faecalis PBP5 is a type II membrane protein with an uncleaved N-terminal and is composed of 679 amino acids with a molecular weight of 74055. This protein showed 48 and 33% of identity with Enterococcus hirae PBP5 and Staphylococcus aureus PBP2a, both low-affinity PBPs involved in β-lactam resistance. Anti-PBP5 antibodies cross-reacted with a membrane protein present in other species of enterococci, but the entire gene fragment cloned hybridized only with DNAs of E. faecalis strains, thus suggesting that genes coding for low-affinity PBPs of enterococci are not stictly homologous. In this experiment digoxigenin-labelled E. faecalis DNA was used. |
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Keywords: | Penicillin binding protein Escherichia coli Enterococcus faecalis Geen sequence |
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