The FB and FA electron acceptors in Photosystem I (PS I) are [4Fe-4S] clusters ligated by cysteines provided by PsaC. In a previous study (Mehari, T., Qiao, F., Scott, M. P., Nellis, D., Zhao, J., Bryant, D., and Golbeck, J. H. (1995) J. Biol. Chem. 270, 28108-28117), we showed that when cysteines 14 and 51 were replaced with serine or alanine, the free proteins contained a S = 1/2, [4Fe-4S] cl...

Pyruvate formate-lyase activating enzyme (PFL-AE) is a representative member of an emerging family of enzymes that utilize iron-sulfur clusters and S-adenosylmethionine (AdoMet) to initiate radical catalysis. Although these enzymes have diverse functions, evidence is emerging that they operate by a common mechanism in which a [4Fe-4S](+) interacts with AdoMet to generate a 5'-deoxyadenosyl radi...

Dysprosium was analyzed using high-resolution high-energy x-ray photoelectron spectroscopy (HAXPES). The HAXPES spectra of dysprosium obtained monochromatic Cr Kα radiation at 5414.8 eV include survey scan and Dy 3s, 3p3/2, 3d5/2, 4s, 4p3/2, 4d, 5p.

We propose a new method to extract the light quark mass ratio m(u)/m(d) using the Υ(4S)→h(b)π⁰(η) bottomonia transitions. The decay amplitudes are dominated by the light quark mass differences, and the corrections from other effects are rather small, allowing for a precise extraction. We also discuss how to reduce the theoretical uncertainty with the help of future experiments. As a by-product,...

lower is a group of transitions involving ls 4p simultaneous with ligand-to-metal shakedown. About 18.7 eV below the main peak is a weak (65 times weaker) quadrupole-allowed transition corresponding to 1s 3d (i.e., ls 3d ls'3d' ). These results are in agreement with typical assignments of x-ray absorption spectra of Cu(tt) systems except that the middle transition is usually assigned as 1s 4s, ...

A novel aminoacyl-tRNA synthetase that contains an iron-sulfur cluster in the tRNA anticodon-binding region and efficiently charges tRNA with tryptophan has been found in Thermotoga maritima. The crystal structure of TmTrpRS (tryptophanyl-tRNA synthetase; TrpRS; EC 6.1.1.2) reveals an iron-sulfur [4Fe-4S] cluster bound to the tRNA anticodon-binding (TAB) domain and an L-tryptophan ligand in the...

We predict that inner-shell ionization of more than one atom (or molecule) in a cluster, e.g., by intense free-electron laser radiation, can lead to an interatomic decay process in which the formed vacancy states decay simultaneously, while a neighboring neutral species is ionized. This collective decay phenomenon can be regarded as a transfer of two or more virtual photons from the ionized clu...

Variation of the relative yield of charged and neutral B mesons across the Υ(4S) resonance Abstract It is shown that the ratio of the production rates of the pairs B + B − and B 0 B 0 should experience a substantial and rapid variation with energy within the width of the Υ(4S) resonance, crossing the value of one near the center of the resonance. This behavior is due to an interference of the r...

In this paper, we report the anisochrony of the fluorine atoms of a CHF₂ group when linked to a pyrazole ring. The pyrazole is part of (4S,7R)-7,8,8-trimethyl-4,5,6,7-tetrahydro-4,7-methano-2H-indazole also known as (4S,7R)-campho[2,3-c]pyrazole, which has two stereogenic centers. Gauge-Independent Atomic Orbital (GIAO)/Becke, 3-parameter, Lee-Yang-Parr (B3LYP)/6-311++G(d,f) calculated 19F chem...

We use two parametrizations of points on elliptic curves in generalized Edwards form x + y = c(1 + dxy) that omit the xcoordinate. The first parametrization leads to a differential addition formula that can be computed using 6M + 4S, a doubling formula using 1M + 4S and a tripling formula using 4M + 7S. The second one yields a differential addition formula that can be computed using 5M + 2S and...