Artigo
Correlation of temperature induced conformation change with optimum catalytic activity in the recombinant G/11 xylanase A from Bacillus subtilis strain 168 (1A1)
Fecha
2005-11-21Registro en:
Febs Letters. Amsterdam: Elsevier B.V., v. 579, n. 28, p. 6505-6510, 2005.
0014-5793
10.1016/j.febslet.2005.10.039
WOS:000233520700034
WOS000233520700034.pdf
9162508978945887
0000-0003-2460-1145
Autor
Universidade Estadual Paulista (Unesp)
Universidade de São Paulo (USP)
Resumen
The 1.7 angstrom resolution crystal structure of recombinant family G/11 beta-1,4-xylanase (rXynA) from Bacillus subtilis 1A1 shows a jellyroll fold in which two curved P-sheets form the active-site and substrate-binding cleft. The onset of thermal denaturation of rXynA occurs at 328 K, in excellent agreement with the optimum catalytic temperature. Molecular dynamics simulations at temperatures of 298-328 K demonstrate that below the optimum temperature the thumb loop and palm domain adopt a closed conformation. However, at 328 K these two domains separate facilitating substrate access to the active-site pocket, thereby accounting for the optimum catalytic temperature of the rXynA. (c) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.