Two-dimensional gel electrophoresis of ribosomal proteins as a novel approach to bacterial taxonomy: application to the genus Arthrobacter.

Abstract

Ribosomal proteins from 22 strains of 15 different species belong to the genus Arthrobacter were analyzed by an improved two-dimensional gel electrophoresis. Electrophoretograms of ribosomal proteins from 15 type strains had species-specific patterns. Similarity coefficients (SAB values) of ribosomal proteins with mol. wt. of greater than about 20,000, among strains of the same species (DNA relatedness values of more than 61%) were greater than 0.85, but the SAB values among strains of different species were less than 0.60. The N-terminal amino acid sequences of the AL2 proteins, which migrated into similar positions in this method, from 5 type strains were shown to be highly homologous. Our results indicated that ribosomal proteins have been conserved within species during evolution and that the members of the genus Arthrobacter are phylogenetically homogeneous. Thus, ribosomal protein profiles by this method are a potential tool for strain identification.