Trinity, polyphony and pastoral relationships

The author explores the Christian doctrine of the Trinity to shed light on the nature of the pastoral ministry. Using the trinitarian term, "polyphony" (David Cunningham) for this purpose, he explicates unity and difference as key polyphonic categories in the doctrine of the Trinity. The author suggests that the polyphonic notes sounded by pastoral caregivers are toughness and tenderness, woundedness and health, wisdom and folly, and communion, nearness and distance.

Cytochrome c(551) from Starkeya novella - Characterization, spectroscopic properties, and phylogeny of a diheme protein of the SoxAX family

Cytochromes from the SoxAX family have a major role in thiosulfate oxidation via the thiosulfate-oxidizing multi-enzyme system (TOMES). Previously characterized SoxAX proteins from Rhodovulum sulficlophilum and Paracoccus pantotrophus contain three heme c groups, two of which are located on the SoxA subunit. In contrast, the SoxAX protein purified from Starkeya novella was found to contain only two heme groups. Mass spectrometry showed that a disulfide bond replaced the second heme group found in the diheme SoxA subunits. Apparent molecular masses of 27,229 +/- 10.3 Da and 20,258.6 +/- 1 Da were determined for SoxA and SoxX with an overall mass of 49.7 kDa, indicating a heterodimeric structure. Optical redox potentiometry found that the two heme cofactors are reduced at similar potentials (versus NHE) that are as follows: + 133 mV (pH 6.0); + 104 mV (pH 7.0); +49 (pH 7.9) and +10 mV (pH 8.7). EPR spectroscopy revealed that both ferric heme groups are in the low spin state, and the spectra were consistent with one heme having a His/Cys axial ligation and the other having a His/Met axial ligation. The His/Cys ligated heme is present in different conformational states and gives rise to three distinct signals. Amino acid sequencing was used to unambiguously assign the protein to the encoding genes, soxAX, which are part of a complete sox gene cluster found in S. novella. Phylogenetic analysis of soxA- and soxX-related gene sequences indicates a parallel development of SoxA and SoxY, with the diheme and monoheme SoxA sequences located on clearly separated branches of a phylogenetic tree.

Crystallization and preliminary X-ray analysis of sulfite dehydrogenase from Stargeya novella

Crystals of purified heterodimeric sulfite dehydrogenase from Starkeya novella have been grown using vapour diffusion. X-ray diffraction data have been collected from crystals of the native protein at lambda=1.0 Angstrom and close to the iron absorption edge at lambda=1.737 Angstrom. The crystals belong to space group P2(1)2(1)2, with unit-cell parameters a=97.5, b=92.5, c=55.9 Angstrom. Native data have been recorded to 1.8 Angstrom resolution and Fe-edge data to 2.5 Angstrom.

Empirical investigation of investment behaviour in Australia's pastoral region

Optimal intertemporal investment behaviour of Australian pastoralists is modelled using panel data for the period 1979-1993. Results indicate that quasi-fixity of inputs of labour, capital, sheep numbers and cattle numbers is characteristic of production in the pastoral region. It takes about two years for labour, four years for capital and a little over two years for both sheep numbers and cattle numbers to adjust towards long-run optimal levels. Results also indicate that, after accounting for adjustment costs, own-price product supply and input demand responses are inelastic in both the short and long run.

Structure of the active site of sulfite dehydrogenase from Starkeya novella

In this paper, we report the results of molybdenum K-edge X-ray absorption studies performed on the oxidized and reduced active sites of the sulfite dehydrogenase from Starkeya novella. Our results provide the first direct structural information on the active site of the oxidized form of this enzyme and confirm the conclusions derived from protein crystallography that the molybdenum coordination is analogous to that of the sulfite oxidases. The molybdenum atom of the oxidized enzyme is bound by two Mo=O ligands at 1.73 angstrom and three thiolate Mo-S ligands at 2.42 angstrom, whereas the reduced enzyme has one oxo at 1.74 angstrom, one long oxygen at 2.19 angstrom (characteristic of Mo-OH2), and three Mo-S ligands at 2.40 angstrom.