Sequence analysis and interposon mutagenesis of the hupT gene, which encodes a sensor protein involved in repression of hydrogenase synthesis in Rhodobacter capsulatus.

AUTOR(ES)

Elsen, S

RESUMO

The hupT gene, which represses hydrogenase gene expression in the purple photosynthetic bacterium Rhodobacter capsulatus, has been identified and sequenced. The nucleotide sequence of hupT and of the contiguous downstream open reading frame, hupU, is reported. The HupT protein of 456 amino acids (48,414 Da) has sequence similarity with the FixL, DctB, NtrB, and ArcB proteins and is predicted to be a soluble sensor kinase. Insertional inactivation of the hupT gene led to deregulation of transcriptional control, so that the hydrogenase structural operon hupSLC became overexpressed in cells grown anaerobically or aerobically. The HupT- mutants were complemented in trans by a plasmid containing an intact copy of the hupT gene. The hupU open reading frame, capable of encoding a protein of 84,879 Da, shared identity with [NiFe]hydrogenase subunits; the strongest similarity was observed with the periplasmic hydrogenase of Desulfovibrio baculatus.

Documentos Relacionados

• Purification and in vitro phosphorylation of HupT, a regulatory protein controlling hydrogenase gene expression in Rhodobacter capsulatus.
• Interaction between the H2 Sensor HupUV and the Histidine Kinase HupT Controls HupSL Hydrogenase Synthesis in Rhodobacter capsulatus
• Identification and sequence analysis of the hupR1 gene, which encodes a response regulator of the NtrC family required for hydrogenase expression in Rhodobacter capsulatus.
• The hupTUV operon is involved in negative control of hydrogenase synthesis in Rhodobacter capsulatus.
• Identification and sequence analysis of genes involved in late steps in cobalamin (vitamin B12) synthesis in Rhodobacter capsulatus.