%0 Journal Article %A Riley, Sean P. %A Bykowski, Tomasz. %A Babb, Kelly %A von Lackum, Kate %A Stevenson, Brian. %T Genetic and physiological characterization of the Borrelia burgdorferi ORF BB0374-pfs-metK-luxS operon %D 2007 %J Microbiology, %V 153 %N 7 %P 2304-2311 %@ 1465-2080 %R https://doi.org/10.1099/mic.0.2006/004424-0 %K RTase, reverse transcriptase %K SAM, S-adenosylmethionine %K AI-2, autoinducer-2 %K Q-RT-PCR, quantitative reverse transcription-PCR %K DPD, 4,5-dihydroxy-2,3-pentanedione %K SAH, S-adenosylhomocysteine %K SRH, S-ribosylhomocysteine %I Microbiology Society, %X The Lyme disease spirochaete, Borrelia burgdorferi, produces the LuxS enzyme both in vivo and in vitro; this enzyme catalyses the synthesis of homocysteine and 4,5-dihydroxy-2,3-pentanedione (DPD) from a by-product of methylation reactions. Unlike most bacteria, B. burgdorferi is unable to utilize homocysteine. However, DPD levels alter expression levels of a subset of B. burgdorferi proteins. The present studies demonstrate that a single B. burgdorferi operon encodes both of the enzymes responsible for synthesis of DPD, as well as the enzyme for production of the Lyme spirochaete's only activated-methyl donor and a probable phosphohydrolase. Evidence was found for only a single transcriptional promoter, located 5′ of the first gene, which uses the housekeeping σ 70 subunit for RNA polymerase holoenzyme function. All four genes are co-expressed, and mRNA levels are growth-rate dependent, being produced during the exponential phase. Thus, high metabolic activity is accompanied by increased cellular levels of the only known borrelial methyl donor, enhanced detoxification of methylation by-products, and increased production of DPD. Therefore, production of DPD is directly correlated with cellular metabolism levels, and may thereby function as an extracellular and/or intracellular signal of bacterial health. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.2006/004424-0