PubMed Health⌕ Search

Biomedical subjects

N J Wood

Publications and source records attributed to N J Wood.

At least 19 recordsLinked to original sources
PubMed1996

Variation in the control region sequence of the sheep mitochondrial genome.

The DNA sequences of the control region of the mitochondrial genome of fifty unrelated sheep were determined in order to ascertain the extent and distribution of its variability. A consensus sequence was derived, and 1081 differences from it were observed amongst the fifty animals. Some constant groups of differences were observed that were held in common by a number of animals, which thus fell into two main groups, although neither group was typical of any of the breeds sampled. The consensus sequence also allowed comparison between the control region sequences of sheep and other mammals. The sequence contains four tandem repeats of a 75 base-pair motif that accounts for the difference in its size from the cattle control region, to which it is otherwise very similar. Comparison with the cattle sequence allowed the determination of the homologues of various functionally important sites. The homologues of the transcription promoters, the origin of replication and the central conserved sequence block were all identified by this method.

Animals↗
PubMed1995

Interaction between primary and secondary metabolism in Streptomyces coelicolor A3(2): role of pyrroline-5-carboxylate dehydrogenase.

The activity of the proline catabolic enzyme pyrroline-5-carboxylate dehydrogenase (EC 1.5.1.12) was induced up to three-hundred-fold by the addition of three hundred proline to the growth medium of the Gram-positive bacterium Streptomyces coelicolor A3(2). Rifampicin, an inhibitor of RNA polymerase activity, abolished induction, implying that regulation was at the level of activation of gene transcription. The enzyme was purified and SDS-PAGE of the highly purified enzyme preparation revealed a single subunit with M(r) 68,000. A single band of protein, which also stained for enzyme activity, was observed after native gel electrophoresis. The M(r) of the enzyme was estimated to be approximately 265,000 by native gel electrophoresis and approximately 305,000 by gel filtration, which indicated that the enzyme had a tetrameric quaternary structure. The apparent Km for pyrroline-5-carboxylate was 109 +/- 7.3 microM, whilst that for NAD+ was 43.3 +/- 2.5 microM. Product inhibition by NADH (apparent Ki 0.6mM) was observed. The observed Vmax was 22.0 +/- 1 mol min-1 (mg protein)-1. Neither 1 nor 5 mM proline had any effect on enzyme activity, whilst glutamate was a very weak inhibitor.

1-Pyrroline-5-Carboxylate Dehydrogenase↗
PubMed1994

Regional mapping of loci from human chromosome 2q to sheep chromosome 2q.

The human chromosome 2q loci, fibronectin 1 (FN1), the alpha 1 chain of type III collagen (COL3A1), and the delta subunit of the muscle acetylcholine receptor (CHRND) have been regionally assigned to sheep chromosome 2q by in situ hybridization. COL3A1 is pericentromeric (2q12-q21), while FN1 and CHRND are in the subterminal region at 2q41-q44 and 2q42-qter, respectively. The mapping of FN1 assigns the sheep syntenic group U11, which contains FN1, villin 1 (VIL1), isocitrate dehydrogenase 1 (IDH1), and gamma subunit of the muscle acetylcholine receptor (CHRNG), to sheep chromosome 2q. Inhibin-alpha (INHA) is also assigned to sheep chromosome 2q as FN1 and INHA compose sheep linkage group 3. These seven loci are members of a conserved chromosomal segment in human, mouse, and sheep.

Animals↗