INVITRO CRYSTALLIZATION OF RIBOSOMES FROM CHICK-EMBRYOS

A new 2-dimensional ribosome crystal, having the tetragonal space group P4212 (a = 593 .ANG.), was grown from ribosome tetramers extracted from hypothermic chick embryos. It is of particular interest because of its larger size (up to 3 .times. 3 .mu.m2) and greater stability compared to other related polymorphic forms, and because it can easily be grown in large amounts. X-ray diffraction shows the order in the crystal to extend to a resolution of at least 60 .ANG.. The crystalline ribsomes appear to contain a full complement of small and large ribosomal subunit proteins and an additional 4 proteins not characteristic of chick embryo polysomes.