Abstract
Uridine phosphorylase (UPH) from Escherichia coli K-12 has been purified to near homogeneity from a strain harbouring the udp gene, encoding UPH, on a multicopy plasmid. UPH was purified to electrophoretic homogeneity with the specific activity 230 units/mg with a recovery of 80%, yielding 120 mg of enzyme from 3g cells. Crystals or enzyme suitable for X-ray diffraction analysis were obtained in a preparative ultracentrifuge. The packing of the molecules in the crystals may be described by the space group P212121 with the unit cell constants a=90.4; b=128.8; c=136.8 A. There is one molecule per asymmetric unit, V(m)=2.4. These crystals diffract to at least 2.5 - 2.7 Å resolution. The hexameric structure or UPH was directly demonstrated by electron microscopy study and image processing.
Original language | English (US) |
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Pages (from-to) | 607-615 |
Number of pages | 9 |
Journal | Biochemistry International |
Volume | 26 |
Issue number | 4 |
State | Published - 1992 |
Keywords
- Cryatallization
- Uridine phosphorylase
- X-ray analysis