CCP4i2 demo data: RNAse (PDB:2SAR)

This structure can be solved quickly by molecular replacement. It can also be solved by experimental phasing using SAD or SIRAS, although the phasing is not very good.

The data are from the crystal structure of ribonuclease from Streptomyces aureofaciens (RNase Sa) and its complex with 3'-guanylic acid (guanosine 3'-monophosphate, 3'-GMP) (Sevcik, J., Dodson, E. J., & Dodson, G. G. (1991). Determination and restrained least-squares refinement of the structures of ribonuclease Sa and its complex with 3'-guanylic acid at 1.8 Å resolution. Acta Crystallographica Section B: Structural Science, 47(2), 240-253.).

The data for the RNAse structure has been collected on 2 crystals, a native, and a Platinum derivative, for which anomalous data has been collected using CuKα radiation. There are estimated to be around 5 Pt atoms per monomer.

The MTZ file contains structure factor amplitudes (not intensities) for both datasets.The native data is in the columns labeled:

FNAT,SIGFNAT

FPTNCD25(+),SIGFPTNCD25(+),FPTNCD25(-),SIGFPTNCD25(-)

Data files

• rnase.fasta RNAse sequence
• rnase25F+F-.mtz MTZ file containing the native data as amplitudes, and anomalous data measured at the Copper Kα wavelength, and a Free-R flag.
• rnase_model.pdb Refined structure.
• 3a5e.pdb MR model with 95% sequence identify.
• 1mgw.pdb MR model with 69% sequence identify.