TY - JOUR
T1 - Genetic and physiological characterization of the Borrelia burgdorferi ORF BB0374-pfs-metK-luxS Operon
AU - Riley, Sean P.
AU - Bykowski, Tomasz
AU - Babb, Kelly
AU - von Lackum, Kate
AU - Stevenson, Brian
PY - 2007/7
Y1 - 2007/7
N2 - 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 σ70 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.
AB - 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 σ70 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.
UR - http://www.scopus.com/inward/record.url?scp=34447527747&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34447527747&partnerID=8YFLogxK
U2 - 10.1099/mic.0.2006/004424-0
DO - 10.1099/mic.0.2006/004424-0
M3 - Article
C2 - 17600074
AN - SCOPUS:34447527747
SN - 1350-0872
VL - 153
SP - 2304
EP - 2311
JO - Microbiology
JF - Microbiology
IS - 7
ER -