The crystal structure of the bovine Rieske iron-sulfur protein indicates a sulfur atom (S-1) of the iron-sulfur cluster and the sulfur atom (Sgamma) of a cysteine residue that coordinates one of the iron atoms form hydrogen bonds with the hydroxyl groups of Ser-163 and Tyr-165, respectively. We have altered the equivalent Ser-183 and Tyr-185 in the Saccharomyces cerevisiae Rieske iron-sulfur pr...

Sulfur abundances have been determined for ten stars to resolve a debate in the literature on the Galactic chemical evolution of sulfur in the halo phase of the Milky Way. Our analysis is based on observations of the S i lines at 9212.9, 9228.1, and 9237.5 Å for stars for which the S abundance was obtained previously from much weaker S i lines at 8694.0 and 8694.6 Å. In contrast to the previous...

It has been hypothesized that the relatively low concentration of sulfur amino acids in legume seeds might be an ecological adaptation to nutrient poor, marginal soils. SARC1 and SMARC1N-PN1 are genetically related lines of common bean (dry bean, Phaseolus vulgaris) differing in seed storage protein composition. In SMARC1N-PN1, the lack of phaseolin and major lectins is compensated by increased...

Ultraviolet (UV) irradiation inhibited sulfur oxidation by cells of Thiobacillus thiooxidans. Sulfur-oxidizing activity decreased as the exposure time to UV light increased. A loss of the ability of cells of fix CO(2) paralleled the loss of sulfur-oxidizing activity. UV light photoinactivated ubiquinone purified from T. thiooxidans. The same percentage of sulfur-oxidizing activity and ubiquinon...

The twospotted spider mite, Tetranychus urticae Koch, is a worldwide pest of numerous agronomic and horticultural plants. Sulfur fungicides are known to induce outbreaks of this pest on several crops, although mechanisms associated with sulfur-induced mite outbreaks are largely unknown. Studies were conducted during 2007-2009 in Oregon and Washington hop yards to evaluate the effect of timing ...

Although a minor constituent of cell and tissues, sulfur is an essential element to fulfil a wide range of biological processes, and it is present in the functional groups of many biomolecules that participate to redox reactions in vivo. Cysteine, one of the two S-containing aminoacids present in proteins, contains sulfur in fully reduced form and its thiol group can undergo a range of reaction...

The 3.45-billion-year-old Strelley Pool Formation of Western Australia preserves stromatolites that are considered among the oldest evidence for life on Earth. In places of exceptional preservation, these stromatolites contain laminae rich in organic carbon, interpreted as the fossil remains of ancient microbial mats. To better understand the biogeochemistry of these rocks, we performed microsc...

1. A preparation of chymotrypsinogen, obtained from Dr. M. Kunitz, was analyzed for sulfur, the sulfur amino acids, tyrosine, and tryptophane. 2. The protein sulfur of chymotrypsinogen was accounted for as methionine, cysteine, and cystine. 3. A method is presented for calculating the minimum molecular weight of a protein from the distribution of the sulfur amino acids. In the case of chymotryp...

The sulfur-binding protein of Thiobacillus ferrooxidans ATCC 23270 was investigated. The protein composition of the bacterium's cell surface changed according to the culture substrate. Sulfur-grown cells showed greater adhesion to sulfur than iron-grown cells. The sulfur-grown cells synthesized a 40-kDa surface protein which was not synthesized by iron-grown cells. The 40-kDa protein had thiol ...