Expression and Regulation of a Silent Operon, hyf, Coding for Hydrogenase 4 Isoenzyme in Escherichia coli†
AUTOR(ES)
Self, William T.
FONTE
American Society for Microbiology
RESUMO
On the basis of hyf-lacZ fusion studies, the hyf operon of Escherichia coli, noted for encoding the fourth hydrogenase isoenzyme (HYD4), is not expressed at a significant level in a wild-type strain. However, mutant FhlA proteins (constitutive activators of the hyc-encoded hydrogenase 3 isoenzyme) activated hyf-lacZ. HyfR, an FhlA homolog encoded by the hyfR gene present at the end of the hyf operon, also activated transcription of hyf-lacZ but did so only when hyfR was expressed from a heterologous promoter. The HYD4 isoenzyme did not substitute for HYD3 in H2 production. Optimum expression of hyf-lacZ required the presence of cyclic AMP receptor protein-cyclic AMP complex and anaerobic conditions when HyfR was the activator.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=305750Documentos Relacionados
- Regulation of the Hydrogenase-4 Operon of Escherichia coli by the σ54-Dependent Transcriptional Activators FhlA and HyfR
- Differential expression of hydrogenase isoenzymes in Escherichia coli K-12: evidence for a third isoenzyme.
- Mutational analysis and characterization of the Escherichia coli hya operon, which encodes [NiFe] hydrogenase 1.
- Anaerobic regulation of the hydrogenase 1 (hya) operon of Escherichia coli.
- Cloning, Characterization, and Functional Expression of the Klebsiella oxytoca Xylodextrin Utilization Operon (xynTB) in Escherichia coli†
