A Study on the C-Terminal Membrane Anchoring of Escherichia coli Penicillin-Binding Protein 5

• Published in: Biochemical and biophysical research communications Vol. 290; no. 1; pp. 427 - 430
• Main Authors: Brandenburg, K., Harris, F., Phoenix, D.A., Seydel, U.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 11.01.2002
• Subjects: Bacterial Proteins; C-terminal α-helix; Carrier Proteins - chemistry; Cell Membrane - metabolism; conformational change; E. coli PBP5; Escherichia coli - metabolism; Hexosyltransferases; Hydrogen-Ion Concentration; Lipids - chemistry; membrane; Muramoylpentapeptide Carboxypeptidase - chemistry; Penicillin-Binding Proteins; Peptides - chemistry; Peptidyl Transferases; Protein Conformation; Protein Structure, Secondary; Protein Structure, Tertiary; Temperature; E. coli PBP5; membrane; conformational change; C-terminal α-helix
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.2001.6198

Escherichia coli penicillin-binding protein 5 (PBP5) anchors to the inner membrane in a pH-dependent manner via a C-terminal amphiphilic α-helix. Low pH was found to enhance both levels of PBP5 membrane anchoring and levels of α-helicity in an aqueous PBP5 C-terminal homologue, which led to the suggestion that levels of PBP5 membrane anchoring are related to levels of PBP5 C-terminal α-helicity. Here we have used Fourier-transformed infrared spectroscopy (FTIR) and a peptide homologue of the PBP5 C-terminal sequence to investigate the effect of pH on the conformational behavior of this sequence at a lipid interface and on its ability to interact with lipid. Our results suggest that the membrane-anchoring mechanism of PBP5 is unlikely to involve conformational change in the protein's C-terminal region and may therefore involve conformational changes in the protein's ectomembranous domain.