PubMed HealthSearch

Biomedical subjects

L Hirth

Publications and source records attributed to L Hirth.

At least 19 recordsLinked to original sources

In vitro translation of tomato bushy stunt virus RNA.

In vitro translation of tomato bushy stunt (TBSV)-RNA in a rabbit reticulocyte system resulted in synthesis of five proteins P 18, P 25, P 34, P 35, and P 40. The P 40 protein was identified as the viral coat protein. Fractionation of TBSV-RNA and subsequent translation provided evidence for the existence of discrete subgenomic RNAs.

Capsid

In vivo dimerization of cauliflower mosaic virus DNA can explain recombination.

Pairs of heterologous cauliflower mosaic virus (CaMV) genomes cloned in pBR322, one having a defective genome and both restricted at the same pBR322 cloning site, generate recombinant molecules in infected cells when co-inoculated on plants. Analysis of the restriction pattern of the isolated recombinant CaMV DNAs indicated that the intergenomic recombination may be explained by dimerization of two heterologous CaMV molecules and transcription into a hybrid 35S RNA responsible for replication of the recombinant genomes.

Base Sequence

Incidence of specific anosmia in Northern Germany.

Thresholds for the perception of 6 primary odorants were tested in a sample of 153 unrelated healthy individuals including 101 males and 52 females. Using some special precautions and directions for preparing aqueous solutions of primary odorants, screening for specific anosmia was found to be a practicable method with reliable results. The observed perception thresholds showed a bimodal distribution. Individuals with higher values probably are specific anosmics. Relatively lower frequencies of anosmia observed in this sample, as compared to reported values in Caucasians of the USA, are probably due to genetic differences. The pheromone character of some odorants and their possible genetic relevance is discussed.

Adolescent

The molecular biology of caulimoviruses.

The molecular biology of the caulimoviruses has already inspired quite a few review articles: this review is limited to a general description of the type-member of this group, namely cauliflower mosaic virus. Details are presented of major results obtained on the organization and function at the molecular level of caulimoviruses and cauliflower mosaic virus in particular.

Base Sequence

Dermatoglyphic findings in patients with fragile X-chromosome.

Finger- and palmar prints of hemi- and heterozygote fragile X-patients with mental retardation (10 males and 5 females) were compared to dermatoglyphic findings in 20 mentally retarded patients (10 males and 10 females) without fragile X and to 200 healthy unrelated persons (100 males and 100 females). Characteristic whorls and double-loops with high ridge-counts on finger-tips and a pronounced transversal course of palmar ridges were restricted to males with fragile X. Female carriers of fragile X showed, corresponding to male patients, some abnormalities of the digital- and palmar ridge-pattern. Contrary to males, in carriers as well as in mentally retarded females without fragile X, fingerprints with low ridge-counts were found. Common to all mentally retarded patients, but more pronounced in males with fragile X, abnormal palmar creases and hand-measurements were observed. These findings probably are related to prenatal retarded growth of the length of the palma and of the middle-finger.

Dermatoglyphics

Ultrasonic absorption evidence of structural fluctuations in viral capsids.

When the coat protein of the small icosahedral virus, brome mosaic virus, reassembles into capsids, the ultrasonic absorption of the solution greatly increases. Submitting the solution to an ultrasonic field thus appears to reveal spontaneous molecular motions within a protein assembly. Confirmatory evidence of a dynamics of a protein shell comes from measurements on brome mosaic virus at various degrees of swelling and on tomato bushy stunt virus treated with the crosslinking agent glutaraldehyde. The detected fluctuations may be related either with cooperative deformational motion in the capsid or with more localized structural changes. Such structural changes may help liberate the RNA at an early stage of viral infection.

Mosaic Viruses

Nucleotide sequence at the 5' extremity of tobacco-mosaic-virus RNA. 1. The noncoding region (nucleotides 1-68).

The sequence of the 5' noncoding region of tobacco mosaic virus RNA has been determined. The noncoding region is 68 nucleotides long and is unusual in that it contains no internal guanosine residues. The long T1 oligonucleotide containing the guanosine-free tract was isolated from a T1 ribonuclease digest of tobacco mosaic virus RNA and sequenced by labelling techniques in vitro using polynucleotide kinase. The guanosine-free tract is terminated by the first potential initiation codon in the RNA molecule and several lines of evidence suggest that this AUG triplet is operational in initiating viral protein synthesis (see following paper). The 5'-noncoding region cannot base-pair extensively with the 3'-terminal sequence of 18-S ribosomal RNA from rabbit reticulocytes.

Base Sequence

Physical map of DNA from a new cauliflower mosaic virus strain.

The restriction enzymes AluI, BamHI, BglII, EcoRI, HindIII, and SalI have been used to characterize and map a new cauliflower mosaic virus strain (Cabb-S). These fragments have been ordered by examining their overlapping regions after double enzymatic digestion. The single SalI cleavage site was chosen as the point of origin. We compare this strain with those already described.

Base Sequence

Valylation of the two RNA components of turnip-yellow mosaic virus and specificity of the tRNA aminoacylation reaction.

A comparative study of the aminoacylation of the two RNA components of turnip yellow mosaic virus, of yeast tRNAVal, tRNAfMet and of tRNAPhe by purified yeast valyl-tRNA synthetase is reported. Aminoacylations were performed in the presence of pure yeast tRNA nucleotidyltransferase, since 85% of the viral RNA molecules lacked the 3'-adenosine. We find that aminoacylation of the viral RNAs, like tRNA aminoacylation, reflects an equilibrium between the acylation and deacylation reactions. The kinetic parameters of TYM virus RNA valylation resemble the values found for tRNAVal valylation; in particular, there is a strong affinity between the viral RNA and valyl-tRNA synthetase and the rate constant for TYM virus RNA valylation is only slightly lower than that for tRNAVal. This result contrasts with the reduced rates observed in tRNA mischarging, and suggests that the viral RNA could be easily aminoacylated in vivo. Considering the fact that the 3'-terminal sequence of TYM virus RNA has only a few points of resemblance to a tRNA sequence, we propose that there are some structural motifs found in both tRNAVal and TYM virus RNA which are brought in a similar spatial arrangement recognized by valyl-tRNA synthetase.

Amino Acyl-tRNA Synthetases

A silent gene (C3-) producing partial deficiency of the third component of human complement.

A family is described with 3 members in 3 generations being heterozygous for the silent gene C3-: one girl, her mother and grandfather had half normal C3 levels and were apparently incompatible homozygous. No significant deviation in the total hemolytic complement activity, serum concentration of Bf and C4 component was found in the affected individuals.

Blood Group Antigens