Figure 3

Physical map of the genomic arrangement of the structural hydrogenase genes, hupSL (depicted in light grey), the putative maturation genes of the small subunit of the uptake hydrogenase (dark grey), and hyp genes (black) of filamentous nitrogen-fixing cyanobacteria. (A) Nostoc sp. strain PCC 7120, (B) Anabaena variabilis ATCC 29413, (C) Nostoc punctiforme PCC 73102, (D) Nodularia spumigena CCY9414, (E) Lyngbya majuscula CCAP 1446/4, and (F) Trichodesmium erythraeum IMS101. The putative maturation genes of the small subunit of the uptake hydrogenase are located in close vicinity to the structural genes, hupSL, and often in between hupSL and the hyp-genes. In Trichodesmium erythraeum IMS101 hupSL and the putative maturation genes are separated from the hyp-gene cluster by approximately 3.8 Mb. *Indicates the N end fragment of the hupL (hupL5'), as annotated in vegetative cells.