Structure determination of a 16.8 kDa copper protein at 2.1 A resolution using anomalous scattering data with direct methods.
Harvey, I., Hao, Q., Duke, E.M., Ingledew, W.J., Hasnain, S.S.(1998) Acta Crystallogr D Biol Crystallogr 54: 629-635
- PubMed: 9761859
- DOI: https://doi.org/10.1107/s0907444998005423
- Primary Citation of Related Structures:
1A8Z - PubMed Abstract:
The structure of rusticyanin, an acid-stable copper protein, has been determined at 2.1 A resolution by direct methods combined with the single-wavelength anomalous scattering (SAS) of copper (f" = 3.9 e-) and then conventionally refined (Rcryst = 18.7%, Rfree = 21.9%). This is the largest unknown protein structure (Mr approximately /= 16.8 kDa) to be determined using the SAS and direct-methods approach and demonstrates that by exploiting the anomalous signal at a single wavelength, direct methods can be used to determine phases at typical (approximately 2 A) macromolecular crystallographic resolutions. Extrapolating from the size of the anomalous signal for copper (f" approximately 4 e-), this result suggests that the approach could be used for proteins with molecular weights of up to 33 kDa per Se (f"max++ = 8 e- at the 'white line') and 80 kDa for a Pt derivative (f"max = 19 e- at the 'white line', L3 edge). The method provides a powerful alternative in solving a de novo protein structure without either preparing multiple crystals (i.e. isomorphous heavy-atom derivative plus native crystals) or collecting multi-wavelength anomalous diffraction (MAD) data.
Organizational Affiliation:
School of Applied Sciences, De Montfort University, The Gateway, Leicester LE1 9BH, England, and CLRC Daresbury Laboratory, Warrington WA4 4AD, England.