1991 Volume 110 Issue 6 Pages 905-908
Two-dimensional crystals of functional chaperonin molecules, which are protein complexes of cpn60 and cpn10, isolated from Thermus thermophilus were prepared on a mercury surface under oxygen atmosphere and were observed by electron microscope after transferring them to carbon coated specimen grids. The crystals showed the hexagonal lattice with unit cell dimensions of a=b=12.4nm and γ=120°. The averaged image at a 3 nm resolution of the chaperonin has a doughnut-like shape which has seven peripheral masses and a central cavity. Preincubation of the chaperonin with MgATP changed the mobility in non-denaturating PAGE but did not cause distinguishable change of shape. The location of cpn10 in the chaperonin molecule is discussed.
