title: Characterization of different crystal forms of the alpha-glucosidase MalA from Sulfolobus solfataricus.
abstract: MalA is an alpha-glucosidase from the hyperthermophilic archaeon Sulfolobus solfataricus. It belongs to glycoside hydrolase family 31, which includes several medically interesting alpha-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 P2(1), from which data sets extending to 2.5 A resolution have been collected. Self-rotation functions calculated for this form and for the orthorhombic (P2(1)2(1)2(1)) form 2 indicate the presence of six molecules in the asymmetric unit related by 32 symmetry.
authors.affiliation: Centre for Crystallographic Studies, Department of Chemistry, University of Copenhagen, Denmark.
authors.forename: Heidi Asschenfeldt
authors.initials: HA
authors.lastname: Ernst
authors.forename: Martin
authors.initials: M
authors.lastname: Willemoës
authors.forename: Leila
authors.initials: L
authors.lastname: Lo Leggio
authors.forename: Gordon
authors.initials: G
authors.lastname: Leonard
authors.forename: Paul
authors.initials: P
authors.lastname: Blum
authors.forename: Sine
authors.initials: S
authors.lastname: Larsen
mesh_terms: D002241:Carbohydrates / Q000737:chemistry; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000378:metabolism; D008320:Maltose / Q000737:chemistry; D009844:Oligosaccharides / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity; D048229:Sulfolobus solfataricus / Q000378:metabolism*; D000520:alpha-Glucosidases / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D009844:Oligosaccharides; D008320:Maltose; D000520:alpha-Glucosidases