Fig. 1. Myxochromide biosynthetic pathways and chemical structures. (i) The mch gene clusters consist of a pks gene (mchA), two nrps genes (mchB and mchC) and mchD (not shown in the figure). The catalytic domains of the encoded PKS/NRPS subunits are illustrated and abbreviated as follows: KS, ketosynthase; AT, acyltransferase; DH, dehydratase; ER, enoylreductase; KR, ketoreductase; CP, carrier protein; C, condensation domain; A, adenylation domain; MT, methyltransferase domain; E, epimerization domain; TE, thioesterase. In the case of NRPS encoding genes, domains are numbered according to the modular organization and the incorporated substrates are indicated. The color filled modules highlight the differences between the A-type and other pathway types. Module deletions are marked with slashes. Domains marked with an asterisk are supposed to be inactive. The figure is reproduced from ref. 24. (ii) Chemical structures of myxochromides.