Crystal packing in two pH-dependent crystal forms of rhamnogalacturonan acetylesterase.
The glycoprotein rhamnogalacturonan acetylesterase from Aspergillus aculeatus has been crystallized in two crystal forms, an orthorhombic and a trigonal crystal form. In the orthorhombic crystal form, the covalently bound carbohydrate at one of the two N-glycosylation sites is involved in crystal contacts. The orthorhombic crystal form was obtained at pH 5.0 and the trigonal crystal form at pH 4.5. In one case, the two crystal forms were found in the same drop at pH 4.7. The differences in crystal packing in the two crystal forms can be explained by the pH-dependent variation in the protonation state of the glutamic acid residues on the protein surface.
Centre for Crystallographic Studies, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark.
Anne
A
Mølgaard
Sine
S
Larsen
D000115:Acetylesterase / Q000737:chemistry*; D001230:Aspergillus / Q000201:enzymology*; D020134:Catalytic Domain; D003460:Crystallization; D018360:Crystallography, X-Ray; D005656:Fungal Proteins / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D017434:Protein Structure, Tertiary; D014867:Water / Q000737:chemistry
D005656:Fungal Proteins; D014867:Water; C096859:rhamnogalacturonan acetylesterase; D000115:Acetylesterase