SEQUENCE VARIATION AS A STRATEGY FOR CRYSTALLIZING RNA MOTIFS

The determination of RNA structures by X-ray crystallography is an exc iting and developing field. At present, the crystallographic character ization of RNA is limited by the difficulty in obtaining large, high q uality crystals. This paper outlines several techniques for improving the likelihood of obtaining RNA crystals, for improving the size of th ose crystals, and for extending the limit of the diffraction maxima. S equence variations have proven to be more effective in changing the qu ality of the crystals than variations in crystallization conditions, o ften making the difference between obtaining true single crystals and multiply twinned crystalline material. (C) 1996 Academic Press Limited