Viruses, Vol. 10, Pages 284: The Auxiliary Role of the Amidase Domain in Cell Wall Binding and Exolytic Activity of Staphylococcal Phage Endolysins

Viruses, Vol. 10, Pages 284: The Auxiliary Role of the Amidase Domain in Cell Wall Binding and Exolytic Activity of Staphylococcal Phage Endolysins Viruses doi: 10.3390/v10060284 Authors: Bokyung Son Minsuk Kong Sangryeol Ryu In response to increasing concern over antibiotic-resistant Staphylococcus aureus, the development of novel antimicrobials has been called for, with bacteriophage endolysins having received considerable attention as alternatives to antibiotics. Most staphylococcal phage endolysins have a modular structure consisting of an N-terminal cysteine, histidine-dependent amidohydrolases/peptidase domain (CHAP), a central amidase domain, and a C-terminal cell wall binding domain (CBD). Despite extensive studies using truncated staphylococcal endolysins, the precise function of the amidase domain has not been determined. Here, a functional analysis of each domain of two S. aureus phage endolysins (LysSA12 and LysSA97) revealed that the CHAP domain conferred the main catalytic activity, while the central amidase domain showed no enzymatic activity in degrading the intact S. aureus cell wall. However, the amidase-lacking endolysins had reduced hydrolytic activity compared to the full-length endolysins. Comparison of the binding affinities of fusion proteins consisting of the green fluorescent protein (GFP) with CBD and GFP with the amidase domain and CBD revealed that the major function of the amidase domain was to enhance the binding affinity of CBD, res...
Source: Viruses - Category: Virology Authors: Tags: Article Source Type: research