5K9Y

Crystal structure of a thermophilic xylanase A from Bacillus subtilis 1A1 quadruple mutant Q7H/G13R/S22P/S179C

Summary for 5K9Y

• Entry DOI: 10.2210/pdb5k9y/pdb
• Descriptor: Endo-1,4-beta-xylanase A (2 entities in total)
• Functional Keywords: glycoside hydrolase family 11, endo-1, 4-beta-xylanase a, thermostability, hydrolase
• Biological source: Bacillus subtilis (strain 168)
• Total number of polymer chains: 2
• Total formula weight: 41094.48

Authors

Pinheiro, M.P.,Ferreira, T.L.,Silva, S.R.B.,Fuzo, C.A.,Silva, S.R.,Lourenzoni, M.R.,Vieira, D.S.,Ward, R.J.,Nonato, M.C. (deposition date: 2016-06-01, release date: 2017-04-12, Last modification date: 2023-09-27)

Primary citation

Silva, S.B.,Pinheiro, M.P.,Fuzo, C.A.,Silva, S.R.,Ferreira, T.L.,Lourenzoni, M.R.,Nonato, M.C.,Vieira, D.S.,Ward, R.J.
The role of local residue environmental changes in thermostable mutants of the GH11 xylanase from Bacillus subtilis.
Int. J. Biol. Macromol., 97:574-584, 2017

PubMed Abstract: A thermostable variant of the mesophilic xylanase A from Bacillus subtilis (BsXynA-G3_4x) contains the four mutations Gln7His, Gly13Arg, Ser22Pro, and Ser179Cys. The crystal structure of the BsXynA-G3_4x has been solved, and the local environments around each of these positions investigated by molecular dynamics (MD) simulations at 328K and 348K. The structural and MD simulation results were correlated with thermodynamic data of the wild-type enzyme, the 4 single mutants and the BsXynA-G3_4x. This analysis suggests that the overall stabilizing effect is entropic, and is consistent with solvation of charged residues and reduction of main-chain flexibility. Furthermore, increased protein-protein hydrogen bonding and hydrophobic interactions also contribute to stabilize the BsXynA-G3_4x. The study revealed that a combination of several factors is responsible for increased thermostability of the BsXynA-G3_4x; (i) introduction of backbone rigidity in regions of high flexibility, (ii) solvation effects and (iii) hydrophobic contacts.

PubMed: 28109807
DOI: 10.1016/j.ijbiomac.2017.01.054

Experimental method

X-RAY DIFFRACTION (2.2 Å)