Model for the formation of the siderophore anachelin 1. Hybrid gene cluster of Anabaena cylindrica PCC 7122 with a NRPS architecture in agreement with the assembly of the characteristic three hydrophilic amino acids (L-Thr-D-Ser-L-Ser) and the two units responsible for binding iron (Atha and Dmaq) of the anachelin 1 structure . In addition, PKS tailoring and transport-related genes are present. Symbol: Cy, cyclisation; A, adenylation; T, thiolation; KACP, KSIII acyl carrier protein; SalS, salicylate synthase; CoAL, salicylyl CoA/PCP ligase; KS, β-ketoacyl synthase; AT, acyltransferase; KR, ketoacyl reductase; ACP, acyl carrier protein; E, epimerase; Red, reductase; MT, methyl transferase; AmT, aminotransferase; TyrH, putative tyrosine hydrolase; SBP, siderophore binding protein; Srec, siderophore receptor; Sal, salicylic acid; Atha, 6-amino-3, 5, 7-trihydroxyheptanoic acid; Thr, threonine; Ser, serine; Dmaq, 1,1-dimethyl-3-amino-1,2,3,4-tetrahydro-6,7-dihydroxyquinolinium. The NRPS genes are indicated in green, the PKS genes are in blue.