Crystallization of the RNA guanylyltransferase of Chlorella virus PBCV-1.
RNA guanylyltransferase, or capping enzyme (E.C. 2.7.7.50) catalyzes the transfer of GMP from GTP to diphosphate-terminated RNA to form the cap structure GpppN. Chlorella virus capping enzyme expressed in E. coli has been purified, treated with GTP and crystallized. X-ray diffraction data have been collected from these crystals as well as for a mercury derivative obtained by soaking the crystals in thimerosal. Selenomethionine RNA guanylyltransferase was purified and crystallized in a similar fashion. The space group is C2221 and the cell parameters are a = 93.3, b = 214.9, c = 105.8 A. Two Hg atoms and two subsets of Se atoms have been localized using difference Patterson and Fourier methods, suggesting that there are two molecules per asymmetric unit.
Laboratory of Molecular Biophysics, University of Oxford, England.
A J
AJ
Doherty
K
K
Håkansson
C K
CK
Ho
S
S
Shuman
D B
DB
Wigley