Crystal structure, at 2.6-A resolution, of the Streptomyces lividans xylanase A, a member of the F family of beta-1,4-D-glycanases.
The crystal structure of the 32-kDa catalytic domain of the Streptomyces lividans xylanase A was solved by molecular isomorphous replacement methods and subsequently refined at 2.6-A resolution to a conventional crystallographic R factor of 0.21. This is the first successful structure determination of a member of the F family of endo-beta-1,4-D-glycanases. Unlike the recently determined xylanases of the G family (Wakarchuk, W. W., Campbell, R. L., Sung, W. L., Davoodi, J., and Yaguchi, M. (1994) Protein Sci. 3, 467-475), where the catalytic domains have a unique beta-sheet structure, the 32-kDa domain of the S. lividans xylanase A is folded into a complete (alpha/beta)8 barrel, the first such fold observed among beta-1,4-D-glycanases. The active site is located at the carbonyl end of the beta barrel. The crystal structure supports the earlier assignment of Glu-128 and Glu-236 as the catalytic amino acids (Moreau, A., Roberge, M., Manin, C., Shareck, F., Kluepfel, D., and Morosoli, R. (1994) Biochem. J., in press).
Derewenda
U
U
Department of Biochemistry, University of Alberta, Edmonton, Canada.
Swenson
L
L
Green
R
R
Wei
Y
Y
Morosoli
R
R
Shareck
F
F
Kluepfel
D
D
Derewenda
Z S
ZS
D001665:Binding Sites; D002480:Cellulase / Q000737:chemistry*; D018360:Crystallography, X-Ray; D043364:Endo-1,4-beta Xylanases; D006026:Glycoside Hydrolases / Q000737:chemistry*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D013302:Streptomyces / Q000201:enzymology*
D006026:Glycoside Hydrolases; D002480:Cellulase; D043364:Endo-1,4-beta Xylanases