Large unit cells virus and ribosome studies

Moffat proposes that the data sets be combined and these occupancies and their associated structures be extracted as a function of time (figure 10.17). This looks like an attractive procedure compared with trying to derive, from one data set alone, details of all conformers present in the crystal at that time. 

The combination of all the advantages of SR is especially needed in virus and ribosome crystallography where the unit cells are very large. Data collection from very large unit cell constant crystals benefits from 

The extreme radiation sensitivity of rhinovirus crystals can be contrasted with poliovirus. Poliovirus was solved using data collected on a conventional X-ray source (Hogle, Chow and Filman 1985) as were various plant viruses much earlier (see Harrison (1978) for a review). 

solved somewhat later than the rhinovirus, also depended totally on SR because of the radiation sensitivity of the crystals and their small size (Acharya et al 1989). 

In the early days of virus crystallography at the synchrotron, the largest lattice constant dealt with was that of cow pea mosaic virus (Usha et al 1984). This virus crystallised in space group P6j22 (or its enantiomorph) with a=451 A and c=1038A. Data collected at LURE (figure 10.18) were analysed and the results showed that quality data 

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Large unit cells (virus and ribosome studies)... 

Table 10.10. Large unit cell structure determinations (including viruses and progress on ribosome studies) based on SR data. (See also table 10.6.)... 

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