TY - JOUR
T1 - Bacillus licheniformis trehalose-6-phosphate hydrolase structures suggest keys to substrate specificity
AU - Lin, Min Guan
AU - Chi, Meng Chun
AU - Naveen, Vankadari
AU - Li, Yi Ching
AU - Lin, Long Liu
AU - Hsiao, Chwan Deng
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Trehalose-6-phosphate hydrolase (TreA) belongs to glycoside hydrolase family 13 (GH13) and catalyzes the hydrolysis of trehalose 6-phosphate (T6P) to yield glucose and glucose 6-phosphate. The products of this reaction can be further metabolized by the energy-generating glycolytic pathway. Here, crystal structures of Bacillus licheniformis TreA (BlTreA) and its R201Q mutant complexed with p-nitrophenyl-α-d-glucopyranoside (R201Q–pPNG) are presented at 2.0 and 2.05 Å resolution, respectively. The overall structure of BlTreA is similar to those of other GH13 family enzymes. However, detailed structural comparisons revealed that the catalytic site of BlTreA contains a long loop that adopts a different conformation from those of other GH13 family members. Unlike the homologous regions of Bacillus cereus oligo-1,6-glucosidase (BcOgl) and Erwinia rhapontici isomaltulose synthase (NX-5), the surface potential of the BlTreA active site exhibits a largely positive charge contributed by the four basic residues His281, His282, Lys284 and Lys292. Mutation of these residues resulted in significant decreases in the enzymatic activity of BlTreA. Strikingly, the281HHLK284 motif and Lys292 play critical roles in substrate discrimination by BlTreA.
AB - Trehalose-6-phosphate hydrolase (TreA) belongs to glycoside hydrolase family 13 (GH13) and catalyzes the hydrolysis of trehalose 6-phosphate (T6P) to yield glucose and glucose 6-phosphate. The products of this reaction can be further metabolized by the energy-generating glycolytic pathway. Here, crystal structures of Bacillus licheniformis TreA (BlTreA) and its R201Q mutant complexed with p-nitrophenyl-α-d-glucopyranoside (R201Q–pPNG) are presented at 2.0 and 2.05 Å resolution, respectively. The overall structure of BlTreA is similar to those of other GH13 family enzymes. However, detailed structural comparisons revealed that the catalytic site of BlTreA contains a long loop that adopts a different conformation from those of other GH13 family members. Unlike the homologous regions of Bacillus cereus oligo-1,6-glucosidase (BcOgl) and Erwinia rhapontici isomaltulose synthase (NX-5), the surface potential of the BlTreA active site exhibits a largely positive charge contributed by the four basic residues His281, His282, Lys284 and Lys292. Mutation of these residues resulted in significant decreases in the enzymatic activity of BlTreA. Strikingly, the281HHLK284 motif and Lys292 play critical roles in substrate discrimination by BlTreA.
KW - Glycoside hydrolase family 13
KW - Trehalose-6-phosphate hydrolase
KW - X-ray crystallography
UR - http://www.scopus.com/inward/record.url?scp=85013042512&partnerID=8YFLogxK
U2 - 10.1107/S2059798315020756
DO - 10.1107/S2059798315020756
M3 - Article
C2 - 26894535
AN - SCOPUS:85013042512
SN - 2059-7983
VL - 72
SP - 59
EP - 70
JO - Acta Crystallographica Section D: Structural Biology
JF - Acta Crystallographica Section D: Structural Biology
IS - 1
ER -