Modular Design of the Bi(multi) functional penicillin-binding proteins

in De pedro; Höltje, J. V.; Loffelhardt, W. (Eds.) Bacterial Growth & Lysis Metabolism and Structure of the Bacterial Sacculus (1993, June 30)

Proceedings of a symposium held in Mallorca, Spain in April 1992. The goal of the meeting was to assess the present state of knowledge on the structure and physiology of the bacterium murien sacculus, and ... [more ▼]

Proceedings of a symposium held in Mallorca, Spain in April 1992. The goal of the meeting was to assess the present state of knowledge on the structure and physiology of the bacterium murien sacculus, and develop new hypotheses and strategies to promote further development of the field. The contributions reflect broadly different approaches. Papers discuss structure and chemistry, biosynthesis and maturation, regulation and control of cell wall hydrolases, penicillin interactive proteins, morphogenesis and septum formation, and cell growth. Annotation c. Book News, Inc., Portland, OR (booknews.com) [less ▲]

Cloning and Sequencing of the Low-Affinity Penicillin-Binding Protein 3r-Encoding Gene of Enterococcus Hirae S185: Modular Design and Structural Organization of the Protein

in Journal of Bacteriology (1993), 175(10), 2844-2852

The clinical isolate Enterococcus hirae S185 has a peculiar mode of resistance to penicillin in that it possesses two low-affinity penicillin-binding proteins (PBPs): the 71-kDa PBP5, also found in other ... [more ▼]

The clinical isolate Enterococcus hirae S185 has a peculiar mode of resistance to penicillin in that it possesses two low-affinity penicillin-binding proteins (PBPs): the 71-kDa PBP5, also found in other enterococci, and the 77-kDa PBP3r. The two PBPs have the same low affinity for the drug and are immunochemically related to each other. The PBP3r-encoding gene has been cloned and sequenced, and the derived amino acid sequence has been compared by computer-assisted hydrophobic cluster analysis with that of the low-affinity PBP5 of E. hirae R40, the low-affinity PBP2' of Staphylococcus aureus, and the PBP2 of Escherichia coli used as the standard of reference of the high-M(r) PBPs of class B. On the basis of the shapes, sizes, and distributions of the hydrophobic and nonhydrophobic clusters along the sequences and the linear amino acid alignments derived from this analysis, the dyad PBP3r-PBP5 has an identity index of 78.5%, the triad PBP3r-PBP5-PBP2' has an identity index of 29%, and the tetrad PBP3r-PBP5-PBP2'-PBP2 (of E. coli) has an identity index of 13%. In spite of this divergence, the low-affinity PBPs are of identical modular design and possess the nine amino acid groupings (boxes) typical of the N-terminal and C-terminal domains of the high-M(r) PBPs of class B. At variance with the latter PBPs, however, the low-affinity PBPs have an additional approximately 110-amino-acid polypeptide stretch that is inserted between the amino end of the N-terminal domain and the carboxy end of the membrane anchor. While the enterococcal PBP5 gene is chromosome borne, the PBP3r gene appears to be physically linked to the erm gene, which confers resistance to erythromycin and is known to be plasmid borne in almost all the Streptococcus spp. examined. [less ▲]

Primary and Predicted Secondary Structures of the Actinomadura R39 Extracellular DD-Peptidase, a Penicillin-Binding Protein (PBP) Related to the Escherichia coli PBP4

in Biochemical Journal (1992), 282(Pt 3), 781-788

As derived from gene cloning and sequencing, the 489-amino-acid DD-peptidase/penicillin-binding protein (PBP) produced by Actinomadura R39 has a primary structure very similar to that of the Escherichia ... [more ▼]

As derived from gene cloning and sequencing, the 489-amino-acid DD-peptidase/penicillin-binding protein (PBP) produced by Actinomadura R39 has a primary structure very similar to that of the Escherichia coli PBP4 [Mottl, Terpstra & Keck (1991) FEMS Microbiol. Lett. 78, 213-220]. Hydrophobic-cluster analysis of the two proteins shows that, providing that a large 174-amino-acid stretch is excluded from the analysis, the bulk of the two polypeptide chains possesses homologues of the active-site motifs and secondary structures found in the class A β-lactamase of Streptomyces albus G of known three-dimensional structure. The 74-amino-acid insert occurs at equivalent places in the two PBPs, between helices α2 and α3, away from the active site. Such an insert is unique among the penicilloyl serine transferases. It is proposed that the Actinomadura R39 PBP and E. coli PBP4 form a special class, class C, of low-Mr PBPs/DD-peptidases. A vector has been constructed and introduced by electrotransformation in the original Actinomadura R39 strain, allowing high-level expression and secretion of the DD-peptidase/PBP (250 mg . 1-1). The gene encoding the desired protein is processed differently in Actinomadura R39 and Streptomyces lividans. Incorrect processing in Streptomyces lividans leads to a secreted protein which is inert in terms of DD-peptidase activity and penicillin-binding capacity. [less ▲]

Amino Acid Sequence of the Penicillin-Binding Protein/DD-Peptidase of Streptomyces K15. Predicted Secondary Structures of the Low Mr Penicillin-Binding Proteins of Class A

in Biochemical Journal (1991), 279(Pt 1), 223-230

The low-Mr penicillin-binding protein (PBP)/DD-transpeptidase of Streptomyces K15 is synthesized in the form of a 291-amino acid-residue precursor possessing a cleavable 29-amino acid-residue signal ... [more ▼]

The low-Mr penicillin-binding protein (PBP)/DD-transpeptidase of Streptomyces K15 is synthesized in the form of a 291-amino acid-residue precursor possessing a cleavable 29-amino acid-residue signal peptide. Sequence-similarity searches and hydrophobic-cluster analysis show that the Streptomyces K15 enzyme, the Escherichia coli PBPs/DD-carboxy-peptidases 5 and 6, the Bacillus subtilis PBP/DD-carboxypeptidase 5 and the spoIIA product (a putative PBP involved in the sporulation of B. subtilis) are structurally related and form a distinct class A of low-Mr PBPs/DD-peptidases. The distribution of the hydrophobic clusters along the amino acid sequences also shows that the Streptomyces K15 PBP, and by extension the other PBPs of class A, have similarity in the polypeptide folding, with the beta-lactamases of class A, with as reference the Streptomyces albus G and Staphylococcus aureus beta-lactamases of known three-dimensional structure. This comparison allows one to predict most of the secondary structures in the PBPs and the amino acid motifs that define the enzyme active sites. [less ▲]