FIG 4.

Genetic organizations of the regions containing habitat-associated gene clusters. Details of the habitat-associated accessory genes are shown in Data Set S1. Differential genes between the two ecological groups are marked with yellow background. (A) The nan gene cluster for sialic acid catabolism. (B) The gvp gene cluster for gas vesicle biosynthesis. Red lines between the two groups indicate corresponding homologous genes. (C) The gene clusters for griseobactin biosynthesis and the cobalt transport system. Genes griE, dhbA, dhbB, dhbG, and cbiO are habitat unassociated because some strains of clade I also contain corresponding homologous genes with low identity. DHBA, 2,3-dihydroxybenzoate; NRPS, nonribosomal peptide synthetase.