TY - JOUR

T1 - Functional characterization and crystal structure of thermostable amylase from Thermotoga petrophila, reveals high thermostability and an unusual form of dimerization

AU - Hameed, Uzma

AU - Price, Ian

AU - Ikram-Ul-Haq, null

AU - Ke, Ailong

AU - Wilson, David B

AU - Mirza, Osman

N1 - Copyright © 2017 Elsevier B.V. All rights reserved.

PY - 2017/10

Y1 - 2017/10

N2 - Thermostable α-amylases have many industrial applications and are therefore continuously explored from novel sources. We present the characterization of a novel putative α-amylase gene product (Tp-AmyS) cloned from Thermotoga petrophila. The purified recombinant enzyme is highly thermostable and able to hydrolyze starch into dextrin between 90 and 100°C, with optimum activity at 98°C and pH8.5. The activity increased in the presence of Rb(1+), K(1+) and Ca(2+) ions, whereas other ions inhibited activity. The crystal structure of Tp-AmyS at 1.7Å resolution showed common features of the GH-13 family, however was apparently found to be a dimer. Several residues from one monomer interacted with a docked acarbose, an inhibitor of Tp-AmyS, in the other monomer, suggesting catalytic cooperativity within the dimer. The most striking feature of the dimer was that it resembled the dimerization of salivary amylase from a previous crystal structure, and thus could be a functional feature of some amylases.

AB - Thermostable α-amylases have many industrial applications and are therefore continuously explored from novel sources. We present the characterization of a novel putative α-amylase gene product (Tp-AmyS) cloned from Thermotoga petrophila. The purified recombinant enzyme is highly thermostable and able to hydrolyze starch into dextrin between 90 and 100°C, with optimum activity at 98°C and pH8.5. The activity increased in the presence of Rb(1+), K(1+) and Ca(2+) ions, whereas other ions inhibited activity. The crystal structure of Tp-AmyS at 1.7Å resolution showed common features of the GH-13 family, however was apparently found to be a dimer. Several residues from one monomer interacted with a docked acarbose, an inhibitor of Tp-AmyS, in the other monomer, suggesting catalytic cooperativity within the dimer. The most striking feature of the dimer was that it resembled the dimerization of salivary amylase from a previous crystal structure, and thus could be a functional feature of some amylases.

KW - Journal Article

U2 - 10.1016/j.bbapap.2017.06.015

DO - 10.1016/j.bbapap.2017.06.015

M3 - Journal article

C2 - 28648523

VL - 1865

SP - 1237

EP - 1245

JO - B B A - Proteins and Proteomics

JF - B B A - Proteins and Proteomics

SN - 1570-9639

IS - 10

ER -