Overcoming a hemihedral twinning problem in tetrahydrofolate-dependent O -demethylase crystals by the microseeding method
A tetrahydrofolate-dependentO-demethylase, LigM, fromSphingobiumsp. SYK-6 was crystallized by the hanging-drop vapour-diffusion method. However, the obtainedP3121 orP3221 crystals, which diffracted to 2.5–3.3 Å resolution, were hemihedrally twinned. To overcome the twinning problem, microseeding usingP3121/P3221 crystals as microseeds was performed with optimization of the reservoir conditions. As a result, another crystal form was obtained. The newly obtained crystal diffracted to 2.5–3.0 Å resolution and belonged to space groupP21212, with unit-cell parametersa= 102.0,b= 117.3,c= 128.1 Å. TheP21212 crystals diffracted to better than 2.0 Å resolution after optimizing the cryoconditions. Phasing using the single anomalous diffraction method was successful at 3.0 Å resolution with a Pt-derivative crystal. This experience suggested that microseeding is an effective method to overcome the twinning problem, even when twinned crystals are utilized as microseeds.
- Research Organization:
- Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
- Sponsoring Organization:
- FOREIGN
- OSTI ID:
- 1334811
- Journal Information:
- Acta Crystallographica. Section F, Structural Biology Communications, Journal Name: Acta Crystallographica. Section F, Structural Biology Communications Journal Issue: 12 Vol. 72; ISSN 2053-230X
- Publisher:
- International Union of Crystallography
- Country of Publication:
- United States
- Language:
- ENGLISH
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