The regulatory genes R1, R2 and R3 do not seem to form an operon, and the arrangement and orientation of these find more genes selleck chemicals llc between each other are conserved

in the gene clusters from HW UTEXB1830, HW IC-52-3, WI HT-29-1 and FS PCC9431. By comparing the identified hapalindole-like natural products with their encoded gene clusters and proposed biosynthesis, the presence/absence of specific genes may be used to predict which class of hapalindole-type natural products (either hapalindole, ambiguines or welwitindolinones) may be produced from newly identified gene clusters. For example, the presence of AmbP3 suggests the ability to produce the ambiguines. This knowledge was used to infer the biosynthesis of the hapalindole-type natural products Wortmannin solubility dmso from FS PCC9339, FS PCC9431 and FM SAG1427-1, since the metabolite profile of these organisms has not been determined. It is likely that the gene cluster from FS PCC9339 encodes the biosynthesis of the hapalindoles, and the gene clusters from FS PCC9431 and FM SAG1427-1 encode the biosynthesis of the welwitindolinones. The gene cluster

from FM SAG1427-1 was grouped with the wel gene clusters based on the presence and high similarity of the genes O18, O19, R3 and M2, all of which are specific to the wel gene clusters. However, the genes located on either side of the wel gene cluster from FM SAG1427-1 display no similarity to other genes in the wel gene clusters, and some highly conserved genes are missing. Carbohydrate The absence of conserved core wel genes suggests the gene cluster may be non-functional in this strain. In order to assess the mechanism of inheritance of hpi/amb/wel gene clusters within the Subsection V strains, we performed phylogenetic analysis of the 16S rDNA (Figure 3). All of the strains that either contain the hpi/amb/wel gene cluster or are known producers of these molecules appear to be a monophyletic group, indicating that the gene cluster first appeared

in a single ancestral strain. This is interesting, considering that some well-studied cyanobacterial natural products, such as microcystin and saxitoxin, exhibit a scattered distribution across several genera [11,12]. Studies suggest that the scattered distribution of these molecules occurs as a result of horizontal gene transfer [11–13]. The hapalindole family of molecules, however, appears to have been only inherited vertically to each of the descendant strains. This pattern of inheritance is also supported by a phylogenetic tree constructed using the prenyltransferase P1 protein sequence, which shows a similar clustering of sequences to the 16S rDNA tree (Additional file 2). The conserved inheritance of these gene clusters implies that the hapalindole family of compounds plays an important role in the producing strains. Figure 3 Phylogenetic analysis of Subsection V strains using 16S rDNA.