Title

Expression and regulation of a silent operon, hyf, coding for hydrogenase 4 isoenzyme in Escherichia coli

Authors

Authors

W. T. Self; A. Hasona;K. T. Shanmugam

Comments

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Abbreviated Journal Title

J. Bacteriol.

Keywords

FORMATE HYDROGENLYASE SYSTEM; MOLYBDATE TRANSPORT OPERON; TRANSCRIPTIONAL ACTIVATOR; MUTATIONAL ANALYSIS; GENE-PRODUCT; NUCLEOTIDE-SEQUENCE; NIFE HYDROGENASE-1; MODE-MOLYBDATE; H-2 METABOLISM; NAR OPERONS; Microbiology

Abstract

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 H-2 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.

Journal Title

Journal of Bacteriology

Volume

186

Issue/Number

2

Publication Date

1-1-2004

Document Type

Article

Language

English

First Page

580

Last Page

587

WOS Identifier

WOS:000188066800036

ISSN

0021-9193

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