Ring-shaped miniparticles with 110A outer diameter which stack up to to form tetrameric rectangular particles (110 X 150A) are ubiquitous in eukaryotic cells. This communication reviews the properties of these miniparticles and shows that the ring-shaped miniparticles are not high-Mr aminoacyl-tRNA synthetase complexes but are a recently recognized 19S RNP particle which represses cytoplasmic mRNA translation.