Characterization and Transcriptional Regulation of n -Alkane Hydroxylase Gene Cluster of Rhodococcus jostii RHA1

• Published in: Microorganisms (Basel) Vol. 7; no. 11; p. 479
• Main Authors: Gibu, Namiko, Kasai, Daisuke, Ikawa, Takumi, Akiyama, Emiko, Fukuda, Masao
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 23.10.2019; MDPI
• Subjects: ALK protein; Alkanes; Deactivation; Degradation; E coli; Gene regulation; Gene silencing; Genes; Genomes; Genomics; Growth rate; Hydrocarbons; Hydroxylase; Inactivation; Mutation; n-alkane; n-alkane hydroxylase; Plasmids; Reverse transcription; Rhodococcus; Rhodococcus jostii; tetr-type transcriptional regulator; United States > US; Japan; Rhodococcus; n-alkane; TetR-type transcriptional regulator; n-alkane hydroxylase
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms7110479

Gram-positive actinomycete RHA1 is able to grow on C10 to C19 -alkanes as a sole source of carbon and energy. To clarify, the -alkane utilization pathway-a cluster of 5 genes ( ) which appeared to be involved in -alkane degradation-was identified and the transcriptional regulation of these genes was characterized. Reverse transcription-PCR analyses revealed that these genes constituted an operon and were transcribed in the presence of -alkane. Inactivation of led to the absence of the ability to utilize -undecane. The mutation resulted in reduction of growth rates on C10 and C12 -alkanes; however, growths on C13 to C19 -alkanes were not affected by this mutation. These results suggested that was essential for the utilization of C10 to C12 -alkanes. Inactivation of showed the constitutive expression of . Purified AlkU is able to bind to the putative promoter region of , suggesting that AlkU played a role in repression of the transcription of operon. The results of this study indicated that was involved in the medium-chain -alkanes degradation of strain RHA1 and the transcription of operon was negatively regulated by -encoded regulator. This report is important to understand the -alkane degradation pathway of , including the transcriptional regulation of gene cluster.