Selenomethionine substitution of orotidine-5'-monophosphate decarboxylase causes a change in crystal contacts and space group

TY - JOUR

T1 - Selenomethionine substitution of orotidine-5'-monophosphate decarboxylase causes a change in crystal contacts and space group

AU - Poulsen, Jens-Christian Navarro

AU - Harris, Pernille Hanne

AU - Jensen, Kaj Frank

AU - Larsen, Sine

N1 - Keywords: orotidine 5'-monophosphate decarboxylase; selenomethionine substitution.

PY - 2001

Y1 - 2001

N2 - Orotidine 5'-monophosphate decarboxylase (ODCase) catalyses the decarboxylation of orotidine 5'-monophosphate to uridine 5'-monophosphate, the last step in the de novo biosynthesis of uridine 5'-monophosphate. In order to determine the structure of ODCase from Escherichia coli by the multi-wavelength anomalous dispersion technique, both native and SeMet-substituted proteins have been produced and purified. During the production of SeMet ODCase, it was observed that SeMet was the only amino acid that it was necessary to add to the defined medium during expression. SeMet-substituted ODCase in complex with the inhibitor 1-(5'-phospho--D-ribofuranosyl)barbituric acid crystallizes under similar conditions as the native enzyme. In contrast to the native enzyme, where the crystals belong to the orthorhombic space group P212121, the SeMet-substituted enzyme crystallizes in the monoclinic space group P21, with a quadrupling of the volume of the asymmetric unit. Despite the drastic difference in symmetry, the overall crystal packing is effectively identical in the two crystal forms. The change in space group appears to originate in differences in the crystal contacts near the SeMet and Met residues. These differences can be rationalized in terms of SeMet's larger size and hydrophobicity.

AB - Orotidine 5'-monophosphate decarboxylase (ODCase) catalyses the decarboxylation of orotidine 5'-monophosphate to uridine 5'-monophosphate, the last step in the de novo biosynthesis of uridine 5'-monophosphate. In order to determine the structure of ODCase from Escherichia coli by the multi-wavelength anomalous dispersion technique, both native and SeMet-substituted proteins have been produced and purified. During the production of SeMet ODCase, it was observed that SeMet was the only amino acid that it was necessary to add to the defined medium during expression. SeMet-substituted ODCase in complex with the inhibitor 1-(5'-phospho--D-ribofuranosyl)barbituric acid crystallizes under similar conditions as the native enzyme. In contrast to the native enzyme, where the crystals belong to the orthorhombic space group P212121, the SeMet-substituted enzyme crystallizes in the monoclinic space group P21, with a quadrupling of the volume of the asymmetric unit. Despite the drastic difference in symmetry, the overall crystal packing is effectively identical in the two crystal forms. The change in space group appears to originate in differences in the crystal contacts near the SeMet and Met residues. These differences can be rationalized in terms of SeMet's larger size and hydrophobicity.

U2 - 10.1107/S0907444901010393

DO - 10.1107/S0907444901010393

M3 - Journal article

SN - 0907-4449

VL - 57

SP - 1251

EP - 1259

JO - Acta Crystallographica. Section D: Biological Crystallography

JF - Acta Crystallographica. Section D: Biological Crystallography

IS - 9

ER -