title: Polycyclic aromatic hydrocarbon degrading gene islands in five pyrene-degrading  Mycobacterium  isolates from different geographic locations.
abstract: Mycobacterium  sp. strain KMS utilizes pyrene, a high-molecular weight polycyclic aromatic hydrocarbon (PAH), as a sole carbon source. Bioinformatic analysis of the genome of isolate KMS predicted 25 genes with the potential to encode 17 pyrene-induced proteins identified by proteomics; these genes were clustered on both the chromosome and a circular plasmid. RT-PCR analysis of total RNA isolated from KMS cells grown with or without pyrene showed that the presence of pyrene increased the transcript accumulation of 20 of the predicted chromosome- and plasmid-located genes encoding pyrene-induced proteins. The transcribed genes from both the chromosome and a circular plasmid were within larger regions containing genes required for PAH degradation constituting PAH-degrading gene islands. Genes encoding integrases and transposases were found within and outside the PAH-degrading gene islands. The lower GC content of the genes within the gene island (61%-64%) compared with the average genome content (68%) suggested that these mycobacteria initially acquired these genes by horizontal gene transfer. Synteny was detected for the PAH-degrading islands in the genomes of two additional Mycobacterium isolates from the same PAH-polluted site and of two other pyrene-degrading Mycobacterium from different sites in the United States of America. Consequently, the gene islands have been conserved from a common ancestral strain.
authors.affiliation: Biology Department, Utah State University, Logan, Utah 84322-5305, USA.
authors.forename: Chun
authors.initials: C
authors.lastname: Zhang
authors.forename: Anne J
authors.initials: AJ
authors.lastname: Anderson
mesh_terms: D001673:Biodegradation, Environmental; D002876:Chromosomes, Bacterial / Q000235:genetics; D020440:Gene Duplication; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial / Q000235:genetics*; D044404:Genomic Islands / Q000235:genetics*; D005810:Multigene Family / Q000235:genetics; D009161:Mycobacterium / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D011721:Pyrenes / Q000378:metabolism* / Q000494:pharmacology; D012689:Sequence Homology, Nucleic Acid; D026801:Synteny; D014481:United States; D014874:Water Pollutants, Chemical / Q000494:pharmacology
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D014874:Water Pollutants, Chemical