Zif, the zoocin A immunity factor, is a FemABX-like immunity protein with a novel mode of action
| Autor: | Paul A. LeBlanc, Shaw R. Gargis, Maria M. Senn, Gary L. Sloan, Lucie S. Heath, Harry E. Heath, Robin S. Simmonds, Brigitte Berger-Bächi, Amy S. Gargis |
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| Rok vydání: | 2009 |
| Předmět: |
Physiology
Lysin Peptidoglycan Biology Applied Microbiology and Biotechnology law.invention Cell wall chemistry.chemical_compound Viral Proteins Mucoproteins Bacterial Proteins law Cell Wall Tandem Mass Spectrometry Drug Resistance Bacterial medicine Streptococcus equi Chromatography High Pressure Liquid chemistry.chemical_classification Ecology Endopeptidase Amino acid Anti-Bacterial Agents carbohydrates (lipids) Enzyme chemistry Biochemistry Mechanism of action Recombinant DNA medicine.symptom Food Science Biotechnology |
| Zdroj: | Applied and environmental microbiology. 75(19) |
| ISSN: | 1098-5336 |
| Popis: | Producer cell immunity to the streptococcolytic enzyme zoocin A, which is a d -alanyl- l -alanine endopeptidase, is due to Zif, the zoocin A immunity factor. Zif has high degrees of similarity to MurM and MurN (members of the FemABX family of proteins), which are responsible for the addition of amino acids to cross bridges during peptidoglycan synthesis in streptococci. In this study, purified peptidoglycans from strains with and without zif were compared to determine how Zif modifies the peptidoglycan layer to cause resistance to zoocin A. The peptidoglycan from each strain was hydrolyzed using the streptococcolytic phage lysin B30, and the resulting muropeptides were separated by reverse-phase high-pressure liquid chromatography, labeled with 4-sulfophenyl isothiocyanate, and analyzed by tandem mass spectrometry in the negative-ion mode. It was determined that Zif alters the peptidoglycan by increasing the proportion of cross bridges containing three l -alanines instead of two. This modification decreased binding of the recombinant target recognition domain of zoocin A to peptidoglycan. Zif-modified peptidoglycan also was less susceptible to hydrolysis by the recombinant catalytic domain of zoocin A. Thus, Zif is a novel FemABX-like immunity factor because it provides resistance to a bacteriolytic endopeptidase by lengthening the peptidoglycan cross bridge rather than by causing an amino acid substitution. |
| Databáze: | OpenAIRE |
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