Expression of the phosphonoalanine-degradative gene cluster from Variovorax sp. Pal2 is induced by growth on phosphonoalanine and phosphonopyruvate

• Published in: FEMS microbiology letters 2009-03, Vol.292 (1), p.100-106
• Main Authors: Kulakova, Anna N, Kulakov, Leonid A, Villarreal-Chiu, Juan F, Gilbert, Jack A, McGrath, John W, Quinn, John P
• Format: Article
• Language: English
• Subjects: Alanine - analogs & derivatives; Alanine - metabolism; Artificial Gene Fusion; Bacteriology; Biological and medical sciences; Carbon; carbon-phosphorus hydrolase; Comamonadaceae - genetics; Comamonadaceae - metabolism; Degradation; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; Energy sources; Fundamental and applied biological sciences. Psychology; Gene clusters; Gene Expression; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Gene Order; Genes; Genes, Reporter; Genetics; Genomes; Green fluorescent protein; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Hydrolase; LysR; Marine environment; Microbiology; Molecular Sequence Data; Multigene Family; Offshore structures; phosphonate; phosphonoalanine metabolism; Phosphorus; Polymerase chain reaction; Pyruvates - metabolism; Reverse Transcriptase Polymerase Chain Reaction - methods; RNA, Bacterial - biosynthesis; RNA, Messenger - biosynthesis; RNA-directed DNA polymerase; Sequence Analysis, DNA; Sequence Homology; Transcription; Variovorax
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2008.01477.x

The phosphonopyruvate hydrolase (PalA) found in Variovorax sp., Pal2, is a novel carbon-phosphorus bond cleavage enzyme, which is expressed even in the presence of high levels of phosphate, thus permitting phosphonopyruvate to be used as the sole carbon and energy source. Analysis of the regions adjacent to the palA gene revealed the presence of the five structural genes that constitute the 2-amino-3-phosphonopropionic acid (phosphonoalanine)-degradative operon. Reverse transcriptase-PCR (RT-PCR) experiments demonstrated that all five genes in the operon are transcribed as a single mRNA and that their transcription is induced by phosphonoalanine or phosphonopyruvate. Transcriptional fusions of the regulatory region of the phosphonoalanine degradative operon with the gfp gene were constructed. Expression analysis indicated that the presence of a LysR-type regulator (encoded by the palR gene) is essential for the transcription of the structural genes of the operon. Similar gene clusters were found in the sequenced genomes of six bacterial species from the Alpha-, Beta- and Gammaproteobacteria, and analysis of metagenomic libraries revealed that sequences related to palA are widely spread in the marine environment.