Journal of Microbiology

Research Support, Non-U.S. Gov't

NOTE] Molecular Analysis of the fur (ferric uptake regulator) Gene of a Pathogenic Edwardsiella tarda Strain: Fang Wang , Shuang Cheng , Kun Sun , Li Sun; J. Microbiol. 2008;46(3):350-355. Published online July 5, 2008; DOI: https://doi.org/10.1007/s12275-008-0038-x

Abstract: The gene encoding the Edwardsiella tarda ferric uptake regulator (FurEt) was cloned from a pathogenic E. tarda strain isolated from diseased fish. FurEt shares 90% overall sequence identity with the Escherichia coli Fur (FurEc) and was able to complement the mutant phenotype of a furEc-defective E. coli strain. Mutational analysis indicated that C92S and C95S mutations inactivated FurEt whereas E112K mutation resulted in a superactive FurEt variant. FurEt negatively regulated its own expression; interruption of this regulation impaired bacterial growth, altered the production of certain outer membrane proteins, and attenuated bacterial virulence.

Regulation of nsdD Expression in Aspergillus nidulans: Kap Hoon Han , Kyu-Yong Han , Min-Su Kim , Dong-Beom Lee , Jong-Hak Kim , Suhn-Kee Chae , Keon-Sang Chae , Dong-Min Han; J. Microbiol. 2003;41(3):259-261.

Abstract: The nsdD gene has been predicted to encode a GATA type transcription factor with the type IVb zinc finger DNA binding domain functions in activating sexual development of A. nidulans. In several allelic mutants of nsdD producing truncated NsdD polypeptides lacking the C-terminal zinc finger, the transcription level of nsdD gene was greatly increased. Also in an over-expressed mutant, the transcription under its own promoter was reduced. These results suggest that the expression of nsdD is negatively autoregulated. When the nsdD gene was over-expressed, cleistothecia were formed in excess amounts even in the presence of 0.6M KCl that inhibited sexual development of the wild type. Northern blot analysis revealed that the expression of nsdD was repressed by 0.6M KCl. These results strongly suggest that the inhibition of sexual development by salts was carried out via the nsdD involved regulatory network.

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