Transcriptional regulation of the cyanobacterial bidirectionalHox-hydrogenase

摘要

The overall processes of transcription and its regulation have advanced significantly in the last years,making our understanding of prokaryotic biology more complex and detailed. In fact, a systematicstudy of different aspects of transcriptional regulation opens up outstanding opportunities to improveand develop the perception of complex reaction mechanisms, genetic processes and cell functions. Inclose connection to the cyanobacterial bidirectional hydrogenase, the main hydrogen-evolving enzymein non-nitrogen fixing strains, two novel transcription factors have received increasing attention overthe past five years: a LexA-related protein and the AbrB-like family members. Recent work on theseregulators has produced new insights and advances towards the understanding (and possibleinterconnection) of several regulatory networks in cyanobacteria, namely nitrogen metabolism, redoxresponse, toxin production, CO_2concentrating mechanisms and hydrogen metabolism. The fact that aLexA-related protein and AbrB-like family members have been co-purified in independent laboratoriesstudying different sets of cyanobacterial genes suggests a possible common and/or complementaryfunction of these regulators. In this review, we summarize the knowledge gained thus far regarding thetranscriptional regulation of the cyanobacterial bidirectional hydrogenase, with special focus on theabove mentioned transcription factors. Moreover, we discuss several additional points that warrantsfurther investigation to increase our knowledge in this fast evolving research field.