Abstract
The regular surface layer of a strain of a Comamonas-like organism was examined by electron microscopy. The surface layer protein was easily extracted from the cell surface by a 2.5M solution of lithium chloride. The protein subunit has a molecular size of 32, 000 daltons, but usually forms a large aggregate of more than 1, 200, 000 daltons. In the extract it formed a regular array of p4 symmetry and was observed to be intimately associated with fragments of lipopolysaccharide. The size of a subunit determined by the negative staining method and the image processing method measured 5.2×6.4nm (width and length), was arranged in a cobblestone-like pattern, and was located in a lattice space measuring 13.0nm square.
