Camphor pathway redux: functional recombinant expression of 2,5- and 3,6-diketocamphane monooxygenases of Pseudomonas putida ATCC 17453 with their cognate flavin reductase catalyzing Baeyer-Villiger reactions

Whereas the biochemical properties of the monooxygenase components that catalyze the oxidation of 2,5-diketocamphane and 3,6-diketocamphane (2,5-DKCMO and 3,6-DKCMO, respectively) in the initial catabolic steps of (+) and (−) isomeric forms of camphor metabolism in Pseudomonas putida ATCC 17453 are relatively well characterized, the actual identity of the flavin reductase (Fred) component that provides the reduced flavin to the oxygenases is hitherto ill-defined. In this study, a 37-kDa Fred was purified from camphor-induced culture of P. putida ATCC 17453 and this facilitated cloning and characterization of the requisite protein. The active Fred is a homodimer with a subunit molecular mass of 18-kDa that uses NADH as electron donor (Km = 32 μM) and it catalyzes the reduction of FMN (Km = 3.6 μM; kcat = 283 s-1) in preference to FAD (Km = 19 μM; kcat = 128 s-1). Sequence determination of ∼40-kb of the camphor (CAM) degradation plasmid revealed the locations of two isofunctional 2,5-DKCMO genes (camE25-1 for 2,5-DKCMO-1, and camE25-2 for 2,5-DKCMO-2) as well as that of 3,6-DKCMO-encoding gene (camE36). In addition, by pulsed-field gel electrophoresis, the CAM plasmid was established to be linear and ∼533-kb in length. To enable functional assessment of the two-component monooxygenase system in Baeyer-Villiger oxidations, recombinant plasmids expressing Fred in tandem with the respective 2,5-DKCMO and 3,6-DKCMO encoding genes in Escherichia coli were constructed. Comparative substrate profiling of the isofunctional 2,5-DCKMOs did not yield obvious differences in Baeyer-Villiger biooxidations but they are distinct from 3,6-DKCMO in the stereoselective oxygenations with various mono- and bicyclic ketone substrates

The Dark Matter Haloes and Host Galaxies of MgII Absorbers at z~1

Strong foreground absorption features from singly-ionized Magnesium (Mg II) are commonly observed in the spectra of quasars and are presumed to probe a wide range of galactic environments. To date, measurements of the average dark matter halo masses of intervening Mg II absorbers by way of large-scale cross-correlations with luminous galaxies have been limited to z<0.7. In this work we cross-correlate 21 strong (W{\lambda}2796>0.6 {\deg}A) Mg II absorption systems detected in quasar spectra from the Sloan Digital Sky Survey Data Release 7 with ~32,000 spectroscopically confirmed galaxies at 0.7<z<1.45 from the DEEP2 galaxy redshift survey. We measure dark matter (DM) halo biases of b_G=1.44\pm0.02 and b_A=1.49\pm0.45 for the DEEP2 galaxies and Mg II absorbers, respectively, indicating that their clustering amplitudes are roughly consistent. Haloes with the bias we measure for the Mg II absorbers have a corresponding mass of 1.8(+4.2/-1.6) \times 10^12h-1M_sun, although the actual mean absorber halo mass will depend on the precise distribution of absorbers within DM haloes. This mass estimate is consistent with observations at z=0.6, suggesting that the halo masses of typical Mg II absorbers do not significantly evolve from z~1. We additionally measure the average W{\lambda}2796>0.6 \AA gas covering fraction to be f =0.5 within 60 h-1kpc around the DEEP2 galaxies, and we find an absence of coincident strong Mg II absorption beyond a projected separation of ~40 h-1kpc. Although the star-forming z>1 DEEP2 galaxies are known to exhibit ubiquitous blueshifted Mg II absorption, we find no direct evidence in our small sample linking W{\lambda}2796>0.6 \AA absorbers to galaxies with ongoing star formation.Comment: 12 pages, 5 figures, Accepted to MNRA

Influenza vaccination for immunocompromised patients: systematic review and meta-analysis from a public health policy perspective.

Immunocompromised patients are vulnerable to severe or complicated influenza infection. Vaccination is widely recommended for this group. This systematic review and meta-analysis assesses influenza vaccination for immunocompromised patients in terms of preventing influenza-like illness and laboratory confirmed influenza, serological response and adverse events

The normal levels of immunoglobulins of the mare's uterus

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Bibliography: leaves 69-78.Not availabl

Cloning, sequence and expression of a linear plasmid-based and a chromosomal homolog of chloroacetaldehyde dehydrogenase-encoding genes in Xanthobacter autotrophicus GJ10

NRC publication: Ye

Identification of a membrane protein and a truncated LysR-type regulator associated with the toluene degradation pathway in Pseudomonas putida F1

NRC publication: Ye

Identification of a membrane protein and a truncated LysR-type regulator associated with the toluene degradation pathway in Pseudomonas putida F1

NRC publication: Ye