Extreme heterogeneous composition of the Paramecium caudatum macronuclear genomic DNA between hemoglobin and nucleosome assembly protein-1 genes.

The intergenic region between the hemoglobin (hb) and nucleosome assembly protein-1 (nap-1) genes in the Paramecium caudatum macronuclear genome was previously found to be heterogeneously composed. Cloning of this intergenic region from the macronuclear genomic DNA identified four unique DNA fragments of different sizes. Sequencing of the cloned fragments revealed extreme heterogeneity and characteristics of both internal eliminated sequence (IES) and imprecise internal deletion sequences (IIDSs) in the intergenic region.

The presence of chimeric DNA consisting of 5' regions of the hemoglobin and nucleosome assembly protein-1 genes in Paramecium caudatum macronuclear genomic DNA.

We detected an unexpected small-sized DNA fragment during polymerase chain reaction (PCR) analysis of the heterogeneity of a macronuclear intergenic region of Paramecium caudatum. Southern blotting of total genomic DNA with the PCR product as a probe indicated that the small-sized DNA fragment constituted part of the macronuclear genome. Sequencing revealed that the PCR product was a chimeric DNA structure that may be generated by tail-to-tail fusion of the 5' region of the hemoglobin (hb) gene to most of the nucleosome assembly protein-1 (nap-1) gene.

Effects of magnesium and calcium on the oxygenation reaction of erythrocruorin from the marine polychaete Arenicola marina and the terrestrial oligochaete Lumbricus terrestris.

Oxygenation function of annelid erythrocruorin (Er) is affected by Mg and Ca concentration in the blood. Four classes of responses may be encountered in different species: 1) Mg=Ca (equal effects), 2) Mg>Ca, 3) Mg View Article and Find Full Text PDF

Yeast flavohemoglobin from Candida norvegensis. Its structural, spectral, and stability properties.

Flavohemoglobin was isolated directly from the yeast Candida norvegensis and studied on its structural, spectral, and stability properties. In Candida flavohemoglobin, the 155 N-terminal residues make a heme-containing domain, while the remaining 234 C-terminal residues serve as a FAD-containing reductase domain. A pair of His-95 and Gln-63 was assigned to the proximal and distal residues, respectively.