Crystal structure of the glycosidase family 73 peptidoglycan hydrolase FlgJ.
Glycoside hydrolase (GH) categorized into family 73 plays an important role in degrading bacterial cell wall peptidoglycan. The flagellar protein FlgJ contains N- and C-terminal domains responsible for flagellar rod assembly and peptidoglycan hydrolysis, respectively. A member of family GH-73, the C-terminal domain (SPH1045-C) of FlgJ from Sphingomonas sp. strain A1 was expressed in Escherichia coli, purified, and characterized. SPH1045-C exhibited bacterial cell lytic activity most efficiently at pH 6.0 and 37 degrees C. The X-ray crystallographic structure of SPH1045-C was determined at 1.74 A resolution by single-wavelength anomalous diffraction. The enzyme consists of two lobes, alpha and beta. A deep cleft located between the two lobes can accommodate polymer molecules, suggesting that the active site is located in the cleft. Although SPH1045-C shows a structural homology with family GH-22 and GH-23 lysozymes, the arrangement of the nucleophile/base residue in the active site is specific to each peptidoglycan hydrolase.
Laboratory of Basic and Applied Molecular Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
Wataru
W
Hashimoto
Akihito
A
Ochiai
Keiko
K
Momma
Takafumi
T
Itoh
Bunzo
B
Mikami
Yukie
Y
Maruyama
Kousaku
K
Murata
D000595:Amino Acid Sequence; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000737:chemistry* / Q000235:genetics; D017434:Protein Structure, Tertiary; D020578:Sphingomonas / Q000201:enzymology*
D009238:N-Acetylmuramoyl-L-alanine Amidase