Publication Abstract from PubMed
The crystal structure of a thermostable endo-1,5-alpha-L-arabinanase, ABN-TS, from Bacillus thermodenitrificans TS-3 was determined at 1.9 A to an R-factor of 18.3% and an R-free-factor of 22.5%. The enzyme molecule has a five-bladed beta-propeller fold. The substrate-binding cleft formed across one face of the propeller is open on both sides to allow random binding of several sugar units in the polymeric substrate arabinan. The beta-propeller fold is stabilized through a ring closure. ABN-TS exhibits a new closure-mode involving residues in the N-terminal region: Phe7 to Gly21 exhibit hydrogen bonds and hydrophobic interactions with the first and last blades, and Phe4 links the second and third blades through a hydrogen bond and an aromatic stacking interaction, respectively. The role of the N-terminal region in the thermostability was confirmed with a mutant lacking 16 amino acid residues from the N-terminus of ABN-TS.
Structural basis for thermostability of endo-1,5-alpha-L-arabinanase from Bacillus thermodenitrificans TS-3.,Yamaguchi A, Tada T, Wada K, Nakaniwa T, Kitatani T, Sogabe Y, Takao M, Sakai T, Nishimura K J Biochem. 2005 May;137(5):587-92. PMID:15944411[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
