Mass spectrometry (MS) is an important tool for studying non-ribosomal peptide, polyketide, and fatty acid biosynthesis. Here we describe a new approach using multi-stage tandem MS on a common ion trap instrument to obtain high-resolution measurements of the masses of substrates and intermediates bound to phosphopantetheinylated (holo) carrier proteins. In particular, we report the chemical for...

The 207-kDa polyketide synthase (PKS) module (residues 1-1895) and the 143-kDa nonribosomal peptidyl synthetase (NRPS) module (1896-3163) of the 350-kDa HMWP1 subunit of yersiniabactin synthetase have been expressed in and purified from Escherichia coli in soluble forms to characterize the acyl carrier protein (ACP) domain of the PKS module and the homologous peptidyl carrier protein (PCP(3)) d...

Messenger RNA 3'-end formation is functionally coupled to transcription by RNA polymerase II. By tagging and purifying Ref2, a non-essential protein previously implicated in mRNA cleavage and termination, we isolated a multiprotein complex, holo-CPF, containing the yeast cleavage and polyadenylation factor (CPF) and six additional polypeptides. The latter can form a distinct complex, APT, in wh...

In a deep, subalpine holo-oligomictic lake, the relative abundance of Archaea and Crenarchaeota, but not that of Bacteria, increases significantly with depth and varies seasonally. Cell-specific prokaryotic productivity is homogeneous along the water column. The concept of active Archaea observed in the deep ocean can therefore be extended to a deep oxic lake.

Mobile computing is been driven by the proliferation of portable devices and wireless communication. Potentially, in the mobile computing scenario, the users can move in different environments and the applications can automatically explore their surroundings. This kind of context-aware application is emerging, but is not yet widely disseminated. Based on perceived context, the application can m...

The structure and backbone dynamics of rat holo cellular retinol-binding protein II (holo-CRBP II) in solution has been determined by multidimensional NMR. The final structure ensemble was based on 3980 distance and 30 dihedral angle restraints, and was calculated using metric matrix distance geometry with pairwise Gaussian metrization followed by simulated annealing. The average RMS deviation ...

The iron-regulated surface determinants (Isd) of Staphylococcus aureus, including surface proteins IsdA, IsdB, IsdC, and IsdH and ATP-binding cassette transporter IsdDEF, constitute the machinery for acquiring heme as a preferred iron source. Here we report hemin transfer from hemin-containing IsdA (holo-IsdA) to hemin-free IsdC (apo-IsdC). The reaction has an equilibrium constant of 10 +/- 5 a...

DeltaFerrin(TM), a yeast-derived recombinant human transferrin produced by Delta Biotechnology Ltd. (Nottingham UK), was found to be a suitable replacement for holo human transferrin in serum-free culture media of the MDCK cell line (chosen because of its transferrin dependence) in short-term screening assays. Long-term subculture was achieved with DeltaFerrin(TM) supporting growth equivalent t...