Mosaic 13 trisomy due to de novo 13/13 translocation with subsequent fission karyotype: 46,XX,-13,+t(13;13)(p11;q11)/46,XX,del(13)(p11)

Summary A severely retarded child with multiple malformations was found to present a mosaic karyotype 46,XX,-13,+t(13;13)(p11;q11)/46,XX,del (13)(p11), which probably originated as the result of a de novo 13/13 translocation in a parental gamete, followed by postzygotic fission of the translocation chromosomse.     

Mosaic 13 trisomy due to de novo 13/13 translocation with subsequent fission. Karyotype: 46,XX,-13, +t(13;13)(p11;q11)/46,XX,del(13)(p11). A second example

In this paper we report a second example of 13 trisomy mosaicism due to de novo 13/13 translocation followed by postzygotic fission of the translocation chromosome in a polymalformed female newborn.     

Probing multiple effects on 15N, 13C alpha, 13C beta,and 13C' chemical shifts in peptides using density functional theory

We have used density functional calculations on model peptides to study conformational effects on (15)N, (13)C alpha, (13)C beta, and (13)C' chemical shifts, associated with hydrogen bonding, backbone conformation, and side-chain orientation. The results show a significant dependence on the backbone torsion angles of the nearest three residues. Contributions to (15)N chemical shifts from hydrogen bonding (up to 8 ppm), backbone conformation (up to 13 ppm), side-chain orientation and neighborhood residue effects (up to 22 ppm) are significant, and a unified theory will be required to account for their behavior in proteins. In contrast to this, the dependence on sequence and hydrogen bonding is much less for (13)C alpha and (13)C beta chemical shifts (<0.5 ppm), and moderate for carbonyl carbon shifts (<2 ppm). The effects of side-chain orientation are mainly limited to the residue itself for both nitrogen and carbon, but the chi(1) effect is also significant for the nitrogen shift of the following residue and for the (13)C' shift of the preceding residue. The calculated results are used, in conjunction with an additive model of chemical shift contributions, to create an algorithm for prediction of (15)N and (13)C shifts in proteins from their structure; this includes a model to extrapolate results to regions of torsion angle space that have not been explicitly studied by density functional theory (DFT) calculations. Crystal structures of 20 proteins with measured shifts have been used to test the prediction scheme. Root mean square deviations between calculated and experimental shifts 2.71, 1.22, 1.31, and 1.28 ppm for N, C alpha, C beta, and C', respectively. This prediction algorithm should be helpful in NMR assignment, crystal and solution structure comparison, and structure refinement.     

A homologous tandem translocation [45,XX,-13,-13,+t(13;13) (q12;q34)

Chromosomal investigation of a young girl with mental and motor retardation and congenital anomalies revealed a translocation between both members of pair No. 13. Banding analysis showed that the translocation was "tandem," leading to monosomy for segments in both the long and short arms of No. 13.     

13C,Ontogeny, and the Paradox of Evolution

The accurate reading of two variants of genetic informatio n is mandatory to perform the ontogenetic program in highly organized multicellular organisms. Physicochemical differences between different portions of the cytoplasm of an egg are insufficient to discriminate these variants. A.A. Ivanov has shown that the formation of differences in the ¹³C isotope content of the DNA copies at early embryological stages is essential for the successful completion of development. Consideration of this fact and the fifth fundamental interaction (the interaction of the spins of macroscopic objects) sheds light on the tremendous delay of the Cambrian explosion.

     

Two Sec13p homologs, AtSec13A and AtSec13B, redundantly contribute to the formation of COPII transport vesicles in Arabidopsis thaliana

COPII vesicles mediate protein transport from ER to Golgi. Sec13 makes up lattice structure with Sec31 to form COPII vesicles. We analyzed expression of two Arabidopsis thaliana Sec13 homologs, AtSec13A and AtSec13B. AtSec13A was expressed in most parts of seedlings, while AtSec13B was partially expressed. Interaction of AtSec13A or AtSec13B with Sec31 homolog was demonstrated by bimolecular fluorescence complementation (BiFC).     

Detection and properties of curvaticin 13, a bacteriocin-like substance produced byLactobacillus curvatus SB13

Lactobacillus curvatus SB13 biosynthetized during growth and excreted into the culture medium an inhibitor active againstListeria monocytogenes, Staphylococcus aureus, and some other Gram-positive bacteria. The native activity was linked to a non-dialyzable proteinaceous complex, destroyed by proteases, with an apparent molecular weight greater that 10 kDa. It showed a hydrophobic character, being soluble in alcohols and not denaturated by several organic solvents. The molecule was partially purified by ammonium sulfate precipitation and hydrophobic interaction chromatography.     

Retinoblastoma, chromosome 13, and in vitro cellular radiosensitivity.

Five diploid fibroblast strains from patients with deletions mapping in the long arm of chromosome 13 and three strains bearing partial trisomies of chromosome 13 were assayed for clonogenic survival following X-irradiation. Results of these experiments suggest the existence of a region on 13q14 which is related to increased sensitivity to cell killing in vitro by X-rays. This locus seems to be distinct from but close to the retinoblastoma locus, which has been associated with the same band.     

Molecular cloning, expression, and purification of SARS-CoV nsp13

The SARS-nsp13 protein was identified as an mRNA cap1 methyltransferase. In this study, the nsp13 gene was cloned from the SARS-CoV PUMC02 strain viral RNA by RT-PCR, and inserted into the expression plasmid pET30a(+). The recombinant plasmid pET30a(+)-nsp13 was confirmed by restriction enzymes and sequencing analysis, and transformed into Escherichia coli BL21(DE3). The His-tag-fused protein was expressed by induction of 0.5mM IPTG and purified by a single Ni(2+) affinity chromatography. The protein was validated by western blot and MS analysis. A large quantity of the nsp13 protein obtained with this method may be useful for further study of its structure and function.