The applicability of the fractal analysis of gravity anomaly to the study of the crustal structure is investigated. Gravity anomaly data in three square areas (175km×175km) in the Japanese Islands with different tectonic settings are analyzed. To study the self-similarity of the gravity anomaly, we adopt the box-counting method to individual contour lines of the gravity anomaly. The contour lines of the gravity anomaly are confirmed to exhibit fractal geometry. The estimated fractal dimensions are in a range of 1.3-1, varying as a function of the gravity anomaly. In order to infer the crustal characteristics we further analyze the relation between the gravity anomaly and the fractal dimension for each area. The observed relations for the three areas are different from each other, reflecting their distinctive crustal structures. The relations can be explained by the lateral variation of depths and the topographic complexity of the subsurface density boundaries.
Monomeric (38kDa) and oligomeric (140kDa) forms of casein kinase II (CK-II) were partially purified from spinach chloroplasts by heparin-agarose column chromatography and gel filtration on Superdex 200 pg (HPLC). The enzymatic properties [requirements of phosphate acceptors and phosphate donors (ATP and GTP), and sensitivity to heparin] of the two kinases exactly corresponded to those reported for various animal CK-IIs. Although poly-Lys and spermine (activators for animal CK-II) stimulated the activity of oligomeric CK-II, no significant effect of these activators on the phosphorylation of casein by monomeric CK-II was detected. Moreover, it has been shown that monomeric CK-II is main form in spinach chloroplasts.
A 34kDa ribonucleoprotein (p34) was purified to homogeneity from a 1.0M KCl extract of spinach chloroplasts as an effective phosphate acceptor for casein kinase II (CK-II) by means of heparin-agarose, DEAE-cellulose, Sephacryl S300, dsDNA-cellulose and Mono Q column chromatography. Biochemical analysis of purified p34 show that the native form of p34 is a monomeric protein and p34 is phosphorylated specifically by CK-II in the chloroplasts.
To understand biological significance of a 34kDa ribonucleoprotein (p34) in the chloroplast gene expression, effects of DNAs and RNAs on the phosphorylation of p34 by CK-II were analyzed biochemically. CK-II catalyzed phosphorylation of p34 was stimulated about 12-fold by dsDNA and 4.2-fold by poly (rG), respectively. The analysis of CD spectra revealed that DNA and RNA induced conformational change of p34. These results suggest that the conformational modification of p34 by nucleic acids results in enhancement of the affinity between the protein and CK-II. Based on the experimental results and findings of previous reports, a possible model for post-transcriptional regulation through phosphorylation of p34 by CK-II in chloroplast gene expression is proposed.
By using the algorithm for identifying transcription units-i.e. independently regulated ORFs and operons, and pseudo-genes, that was described in our earlier paper (Suckow et al., FEBS Letters, in press), the 1, 738, 505 base sequence that covers the whole genome of Pyrococcus sp. OT3 has been analyzed. ORFs of the number, 1, 819, and 51 RNA genes have been identified. For 42% of the identified ORFs significant homology has been found to the known protein genes of known function, and thus these were identified as protein genes, while for 31% homology has been found to the known ORFs of unknown function. For the rest 27% no significant homology has been found.