Fig. 8
The orthoMCL analysis of the predicted proteins containing A, C and/or KS domains in the three assemblies (A), classification of the (B) C and (C) KS domains based on the NaPDoS phylogenetic analysis, and (D) overview of the similarity networks of the AD, C, and KS domains from the Tianshan metagenomes. Network representation of the clades is based on all-versus-all sequence alignments. Each node represents an AD, C, or KS domain, and the edges connect domains with e value < 10− 60. The meaning of the node colors and shapes are given in the figure at the top of the panel. Nodes of reference domains from SwissProt have smaller sized labels. Only clades with more than six nodes and at least one node from the metagenomes are shown. LCL, catalyze formation of a peptide bond between two l-amino acids; DCL, link an l-amino acid to a growing peptide ending with a d-amino acid; Epim, epimerization domains change the chirality of the last amino acid in the chain from L- to D-amino acid; modAA, appear to be involved in the modification of the incorporated amino acid; Start, first module of a NRPS. Modular: modular PKS, large multi-domain enzymes consisting of multiple sets of modules, in which each domain is used only once in the synthesis process following the co-linearity rule; hybridKS: biosynthetic assembly lines that include both PKS and NRPS components; PUFA: Polyunsaturated fatty acids (PUFAs), the long chain fatty acids containing more than one double bond, including omega-3-and omega-6- fatty acids; Enediyne: a family of biologically active natural products [37]; iterative: type I iterative PKS which uses the same domain repeatedly to elongate the polyketide chain [38, 39]