TY - JOUR
T1 - Characterization of the catalytic activity of the γ-phage lysin, PlyG, specific for Bacillus anthracis
AU - Kikkawa, Hitomi S.
AU - Ueda, Takuya
AU - Suzuki, Shin Ichi
AU - Yasuda, Jiro
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2008/9
Y1 - 2008/9
N2 - Bacillus anthracis causes anthrax, a lethal disease affecting humans that has attracted attention due to its bioterrorism potential. PlyG is a lysin of γ-phage, which specifically infects B. anthracis and lyses its cell wall. PlyG contains a T7 lysozyme-like amidase domain, which appears to be the catalytic domain, in the N-terminal region and has a high degree of sequence similarity with PlyL, which is an N-acetylmuramoyl-l-alanine amidase encoded by the B. anthracis genome. Here, we demonstrated that two amino acid residues of PlyG, H29 and E90, are necessary for its catalytic activity in B. anthracis. These residues are structurally analogous to residues whose mutation in T7 lysozyme abolished its catalytic activity. A C-terminal deletion mutant of PlyG lacking the core sequence for binding to B. anthracis showed completely abolished binding activity, unlike PlyL, despite high sequence similarity with PlyL in the N-terminal region. This suggests that the C-terminal binding domain, as well as the N-terminal catalytic domain, is essential for the catalytic activity of PlyG. Our observations provide new insights into the mechanism of specific catalysis of PlyG in B. anthracis and may contribute to the establishment of new methods for anthrax therapy.
AB - Bacillus anthracis causes anthrax, a lethal disease affecting humans that has attracted attention due to its bioterrorism potential. PlyG is a lysin of γ-phage, which specifically infects B. anthracis and lyses its cell wall. PlyG contains a T7 lysozyme-like amidase domain, which appears to be the catalytic domain, in the N-terminal region and has a high degree of sequence similarity with PlyL, which is an N-acetylmuramoyl-l-alanine amidase encoded by the B. anthracis genome. Here, we demonstrated that two amino acid residues of PlyG, H29 and E90, are necessary for its catalytic activity in B. anthracis. These residues are structurally analogous to residues whose mutation in T7 lysozyme abolished its catalytic activity. A C-terminal deletion mutant of PlyG lacking the core sequence for binding to B. anthracis showed completely abolished binding activity, unlike PlyL, despite high sequence similarity with PlyL in the N-terminal region. This suggests that the C-terminal binding domain, as well as the N-terminal catalytic domain, is essential for the catalytic activity of PlyG. Our observations provide new insights into the mechanism of specific catalysis of PlyG in B. anthracis and may contribute to the establishment of new methods for anthrax therapy.
KW - Bacillus anthracis
KW - Catalytic domain
KW - N-acetylmuramoyl-L-alanine amidase
KW - PlyG
KW - T7 lysozyme
KW - γ-phage
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U2 - 10.1111/j.1574-6968.2008.01280.x
DO - 10.1111/j.1574-6968.2008.01280.x
M3 - Article
C2 - 18662316
AN - SCOPUS:49749135789
VL - 286
SP - 236
EP - 240
JO - FEMS Microbiology Letters
JF - FEMS Microbiology Letters
SN - 0378-1097
IS - 2
ER -