BMC Bioinformatics 2006, 7:371.CrossRefPubMed 59. Corander J, Tang J: Bayesian analysis of population structure based on linked molecular information. Math Biosci 2007,205(1):19–31.CrossRefPubMed 60. Gelman A, Carlin JB, Stern HS, Rubin

DB: Bayesian Data Analysis 2 Edition Chapman & Hall/CRC 2004. 61. Krebs C: Ecological Methodology 1 Edition New York: Harper&Collins 1989. Authors’ contributions LK-K and AK conducted the sequence analysis and prepared the manuscript, LP supervised the sequencing library construction procedure, TH-302 chemical structure JC determined the Shannon entropies, HM performed %G+C fractioning of the pooled DNA samples, JT acted as bioinformatics specialist and provided scripts needed in data analysis for LK-K and AK, AP designed and supervised the

study. All authors have contributed in the manuscript writing process as well as approved the final manuscript.”
“Background Cyanobacteria are phototrophic prokaryotes that may contain up to two NiFe-hydrogenases, notably an uptake (encoded by hupSL) and a bidirectional enzyme Ilomastat purchase (encoded by hoxEFUYH). Lyngbya majuscula CCAP 1446/4 is a N2-fixing filamentous nonheterocystous strain in which both hydrogenases are present [1–4]. The biosynthesis/maturation of NiFe-hydrogenases is a complex process, mediated by several accessory proteins, which assure the right assembly of metals and its ligands in the active center and in the electron transport clusters of the large and the small subunit, respectively. The last step in the maturation of the large subunit is the cleavage of a C-terminal peptide 17-DMAG (Alvespimycin) HCl from its precursor. After this cleavage, the mature large subunit assembles with the mature small subunit and eventually the hydrogenase

holoenzyme becomes active [5]. The genes encoding the hydrogenases accessory proteins were first characterized for Escherichia coli, and while most of these proteins affect the hydrogenases pleiotropically (Hyp proteins), the cleavage of the C-terminal peptide is processed by a specific endopeptidase [5, 6]. Several genes presumably involved in the biosynthesis/maturation of cyanobacterial hydrogenases have been identified and characterized, in particular since cyanobacterial genome sequences became available [3, 7–15]. In cyanobacteria, the hyp genes are frequently clustered and located in the vicinity of the structural genes of one of the hydrogenases, with a well known exception – the unicellular Synechocystis sp. strain PCC 6803 – in which hypABCDEF are scattered throughout the genome [for a review see [15]]. Recently, it was unequivocally demonstrated that hypA1, B1, C, D, E and F are required for an active bidirectional hydrogenase in Synechocystis sp. PCC 6803 [11]. The presence of a single copy of most of the hyp genes in cyanobacteria, regardless of possessing only the uptake hydrogenase (e.g. Nostoc punctiforme), the bidirectional hydrogenase (e.g.