Publications

• Dissimilation of cysteate via 3-sulfolactate sulfo-lyase and a sulfate exporter in Paracoccus pantotrophus NKNCYSA.

  Rein U., Gueta R., Denger K., Ruff J., Hollemeyer K., Cook A.M.

  Paracoccus pantotrophus NKNCYSA utilizes (R)-cysteate (2-amino-3-sulfopropionate) as a sole source of carbon and energy for growth, with either nitrate or molecular oxygen as terminal electron acceptor, and the specific utilization rate of cysteate is about 2 mkat (kg protein)(-1). The initial deg ... >> More

  Paracoccus pantotrophus NKNCYSA utilizes (R)-cysteate (2-amino-3-sulfopropionate) as a sole source of carbon and energy for growth, with either nitrate or molecular oxygen as terminal electron acceptor, and the specific utilization rate of cysteate is about 2 mkat (kg protein)(-1). The initial degradative reaction is catalysed by an (R)-cysteate : 2-oxoglutarate aminotransferase, which yields 3-sulfopyruvate. The latter was reduced to 3-sulfolactate by an NAD-linked sulfolactate dehydrogenase [3.3 mkat (kg protein)(-1)]. The inducible desulfonation reaction was not detected initially in cell extracts. However, a strongly induced protein with subunits of 8 kDa (alpha) and 42 kDa (beta) was found and purified. The corresponding genes had similarities to those encoding altronate dehydratases, which often require iron for activity. The purified enzyme could then be shown to convert 3-sulfolactate to sulfite and pyruvate and it was termed sulfolactate sulfo-lyase (Suy). A high level of sulfite dehydrogenase was also induced during growth with cysteate, and the organism excreted sulfate. A putative regulator, OrfR, was encoded upstream of suyAB on the reverse strand. Downstream of suyAB was suyZ, which was cotranscribed with suyB. The gene, an allele of tauZ, encoded a putative membrane protein with transmembrane helices (COG2855), and is a candidate to encode the sulfate exporter needed to maintain homeostasis during desulfonation. suyAB-like genes are widespread in sequenced genomes and environmental samples where, in contrast to the current annotation, several presumably encode the desulfonation of 3-sulfolactate, a component of bacterial spores. << Less

  Microbiology 151:737-747(2005) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Expression, Purification, and Characterization of (<i>R</i>)-Sulfolactate Dehydrogenase (ComC) from the Rumen Methanogen <i>Methanobrevibacter millerae</i> SM9.

  Zhang Y., Schofield L.R., Sang C., Dey D., Ronimus R.S.

  (<i>R</i>)-Sulfolactate dehydrogenase (EC 1.1.1.337), termed ComC, is a member of an NADH/NADPH-dependent oxidoreductase family of enzymes that catalyze the interconversion of 2-hydroxyacids into their corresponding 2-oxoacids. The ComC reaction is reversible and in the biosynthetic direction caus ... >> More

  (<i>R</i>)-Sulfolactate dehydrogenase (EC 1.1.1.337), termed ComC, is a member of an NADH/NADPH-dependent oxidoreductase family of enzymes that catalyze the interconversion of 2-hydroxyacids into their corresponding 2-oxoacids. The ComC reaction is reversible and in the biosynthetic direction causes the conversion of (<i>R</i>)-sulfolactate to sulfopyruvate in the production of coenzyme M (2-mercaptoethanesulfonic acid). Coenzyme M is an essential cofactor required for the production of methane by the methyl-coenzyme M reductase complex. ComC catalyzes the third step in the first established biosynthetic pathway of coenzyme M and is also involved in methanopterin biosynthesis. In this study, ComC from <i>Methanobrevibacter millerae</i> SM9 was cloned and expressed in <i>Escherichia coli</i> and biochemically characterized. Sulfopyruvate was the preferred substrate using the reduction reaction, with 31% activity seen for oxaloacetate and 0.2% seen for <i>α</i>-ketoglutarate. Optimal activity was observed at pH 6.5. The apparent <i>K</i>_M for coenzyme (NADH) was 55.1 <i>μ</i>M, and for sulfopyruvate, it was 196 <i>μ</i>M (for sulfopyruvate the <i>V</i>_max was 93.9 <i>μ</i>mol min^-1 mg^-1 and <i>k</i>_cat was 62.8 s^-1). The critical role of ComC in two separate cofactor pathways makes this enzyme a potential means of developing methanogen-specific inhibitors for controlling ruminant methane emissions which are increasingly being recognized as contributing to climate change. << Less

  Archaea 2017:5793620-5793620(2017) [PubMed] [EuropePMC]