A Linkage Map and Gene Catalog for Escherichia coli

Abstract

This contribution contains a diagram which illustrates the position of about 460 genes on the circular linkage map of this bacterium. In Figure 1 the inner circle, which bears the time scale from 0 through 90 minutes is based on the results of interrupted conjugation experiments. The map is graduated in 1-minute intervals beginning arbitrarily with zero at the thr locus. Certain parts of the map (e. g., the 9- to 10-minute segment) are displayed on arcs of the outer circle to provide an expanded time scale for crowded regions. The genetic symbols in this figure are defined in Table 1. Markers in parentheses are only approximately mapped at the positions shown. A gene identified by an asterisk has been mapped more precisely than the markers in parentheses, but its orientation relative to adjacent markers is not yet known. The arrows which are placed next to the phoA and argI genes and next to certain operons show the direction of messenger RNA transcription for these loci. The table provides an alphabetical listing of these genes and also shows the various specific enzyme activities and other phenotypic traits ascribed to the loci. In Table 1 the numbers refer to the time scale shown in Figure 1. Parentheses indicate approximate map locations. Citations to the scientific publications containing detailed descriptions of each locus under study are given in Taylor (1970) and Taylor and Trotter (1972). Figure 1 and Table 1 are reproduced with the permission of the American Society for Microbiology.