Characterization of different crystal forms of the α-glucosidase MalA from Sulfolobus solfataricus

Authors

Heidi Asschenfeldt Ernst, University of Copenhagen
Martin Willemoës, University of Copenhagen
Leila Lo Leggio, University of Copenhagen
Gordon Leonard, European Synchrotron Radiation Facility (ESRF)
Paul H. Blum, University of Nebraska - LincolnFollow
Sine Larsen, University of Copenhagen

Date of this Version

2005

Citation

Acta Cryst. (2005). F61, 1039–1042

Comments

Copyright 2005 International Union of Crystallography. All rights reserved

Abstract

MalA is an _-glucosidase from the hyperthermophilic archaeon Sulfolobus

solfataricus. It belongs to glycoside hydrolase family 31, which includes several

medically interesting α-glucosidases. MalA and its selenomethionine derivative

have been overproduced in Escherichia coli and crystallized in four different

crystal forms. Microseeding was essential for the formation of good-quality

crystals of forms 2 and 4. For three of the crystal forms (2, 3 and 4) full data sets

could be collected. The most suitable crystals for structure determination are the

monoclinic form 4 crystals, belonging to space group P21, from which data sets

extending to 2.5 Å resolution have been collected. Self-rotation functions

calculated for this form and for the orthorhombic (P2₁2₁2₁) form 2 indicate the

presence of six molecules in the asymmetric unit related by 32 symmetry.