Identification of HU-like protein HCc of Caulobacter crescentus by two-dimensional gel electrophoresis

The 2-D electrophoresis method was used to analyse histone-like proteins of Caulobacter crescentus. This method is a combination of separation in the presence of acetic acid, urea and Triton X-100, and of gradient gel electrophoresis in the presence of SDS. Results obtained earlier were verified, and the method was used to identify the histone-like protein HCc. The HCc protein is probably coded by a single gene because it is composed of identical subunits. The electrophoretic mobility of HCc in the presence of acetic acid, urea and Triton X-100 is intermediate between two subunits of HU. Analysis showed that the apparent molecular weights of both HU and HCc were 13.4-13.5 kD.