plosone-phylo
pone.0005758.g004.png
Gene fusion origin of sxtA.
(a) Schematic diagram illustrating the fusion event that resulted in sxtA (polyketide synthase) in STX+ cyanobacteria. (b) ML phylogenetic tree of sxtA after dividing it into its two phylogenetic components; i.e., sxtA1 (a gene encoding acyl-CoA N-acyltransferase and phosphopantetheine binding domain-containing protein) and sxtA2 (a gene encoding aminotransferase class I and II). ML bootstrap values (when ≥50%) are indicated at the nodes. The branch lengths are proportional to the number of substitutions per site (see scale in the figure). Cyanobacterial taxa are shown in blue text, actinobacteria in brown text, proteobacteria in red text, and other non-cyanobacterial prokaryotes in black. The tree was rooted on the branch separating the two gene fusion partners.
pone.0005758.g004.png
Gene fusion origin of sxtA.
(a) Schematic diagram illustrating the fusion event that resulted in sxtA (polyketide synthase) in STX+ cyanobacteria. (b) ML phylogenetic tree of sxtA after dividing it into its two phylogenetic components; i.e., sxtA1 (a gene encoding acyl-CoA N-acyltransferase and phosphopantetheine binding domain-containing protein) and sxtA2 (a gene encoding aminotransferase class I and II). ML bootstrap values (when ≥50%) are indicated at the nodes. The branch lengths are proportional to the number of substitutions per site (see scale in the figure). Cyanobacterial taxa are shown in blue text, actinobacteria in brown text, proteobacteria in red text, and other non-cyanobacterial prokaryotes in black. The tree was rooted on the branch separating the two gene fusion partners.