Abstract
CAD is a 243 kDa eukaryotic multifunctional polypeptide that catalyzes the first three reactions of de novo pyrimidine biosynthesis: glutamine-dependent carbamyl phosphate synthetase, aspartate transcarbamylase and dihydroorotase (DHO). In prokaryotes, these activities are associated with monofunctional proteins, for which crystal structures are available. However, there is no detailed structural information on the full-length CAD protein or any of its functional domains apart from that it associates to form a homohexamer of ∼1.5 MDa. Here, the expression, purification and crystallization of the DHO domain of human CAD are reported. The DHO domain forms homodimers in solution. Crystallization experiments yielded small crystals that were suitable for X-ray diffraction studies. A diffraction data set was collected to 1.75 Å resolution using synchrotron radiation at the SLS, Villigen, Switzerland. The crystals belonged to the orthorhombic space group C222(1), with unit-cell parameters a=82.1, b=159.3, c=61.5 Å. The Matthews coefficient calculation suggested the presence of one protein molecule per asymmetric unit, with a solvent content of 48%.
Original language | English |
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Journal | Acta Crystallographica Section F: Structural Biology Communications |
Volume | 68 |
Issue number | Pt 11 |
Pages (from-to) | 1341-5 |
Number of pages | 5 |
ISSN | 2053-230X |
DOIs | |
Publication status | Published - 1 Nov 2012 |
Keywords
- Aspartate Carbamoyltransferase/biosynthesis
- Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing)/biosynthesis
- Catalytic Domain
- Chromatography, Affinity
- Chromatography, Gel
- Crystallization
- Crystallography, X-Ray
- Dihydroorotase/biosynthesis
- Escherichia coli
- Humans
- Light
- Protein Structure, Quaternary
- Scattering, Radiation