%0 Journal Article
%T Transcription profiles of hydrogenases related genes in the cyanobacterium Lyngbya majuscula CCAP 1446/4
%A Daniela Ferreira
%A Filipe Pinto
%A Pedro Moradas-Ferreira
%A Marta V Mendes
%A Paula Tamagnini
%J BMC Microbiology
%D 2009
%I BioMed Central
%R 10.1186/1471-2180-9-67
%X In this work we demonstrated that, in L. majuscula, the structural genes encoding the bidirectional hydrogenase are cotranscribed, and that hoxW (the gene encoding its putative specific endopeptidase) is in the same chromosomal region but transcribed from a different promoter. The gene encoding the putative specific uptake hydrogenase endopeptidase, hupW, can be cotranscribed with the structural genes but it has its own promoter. hoxH, hupL, hoxW and hupW transcription was followed in L. majuscula cells grown under N2-fixing and non-N2-fixing conditions over a 12 h light/12 h dark cycle. The transcription of hoxH, hoxW and hupW did not vary remarkably in the conditions tested, while the hupL transcript levels are significantly higher under N2-fixing conditions with a peak occurring in the transition between the light and the dark phase. Furthermore, the putative endopeptidases transcript levels, in particular hoxW, are lower than those of the respective hydrogenase structural genes.The data presented here indicate that in L. majuscula the genes encoding the putative hydrogenases specific endopeptidases, hoxW and hupW, are transcribed from their own promoters. Their transcript levels do not vary notably in the conditions tested, suggesting that HoxW and HupW are probably constantly present and available in the cells. These results, together with the fact that the putative endopeptidases transcript levels, in particular for hoxW, are lower than those of the structural genes, imply that the activity of the hydrogenases is mainly correlated to the transcription levels of the structural genes. The analysis of the promoter regions indicates that hupL and hupW might be under the control of different transcription factor(s), while both hoxH and xisH (hoxW) promoters could be under the control of LexA.Cyanobacteria are phototrophic prokaryotes that may contain up to two NiFe-hydrogenases, notably an uptake (encoded by hupSL) and a bidirectional enzyme (encoded by hoxEFUYH).
%U http://www.biomedcentral.com/1471-2180/9/67