Distribution and complex organization of satellite DNA sequences in Aveneae species.

Distribution, organization, and molecular analysis of four unrelated satellite DNA components in Aveneae species are described. Highly repeated DNA elements were cloned from Helictotrichon convolutum (CON1 and CON2) and Helictotrichon compressum (COM1 and COM2). The lengths of the repeat monomers are 365 bp (CON1), 562 bp (CON2), 346 bp (COM1), and 476 bp (COM2).

Characterization of a highly repeated DNA component of perennial oats (Helictotrichon, Poaceae) with sequence similarity to a A-genome-specific satellite DNA of rice (Oryza).

The taxonomic relationships among perennial oats (Helictotrichon Besser ex Schultes & Schultes, Aveninae, Aveneae, Poaceae) have been studied using highly repeated satellite DNA as a molecular marker. Highly repetitive sequences were isolated from restriction endonuclease digests of nuclear DNA of Helictotrichon convolutum, and satellite repeats (approximately 365 bp in length) were cloned, sequenced and compared among each other. They exhibited an intraspecific sequence variability of 6-9%.

Minimal essential domains specifying toxicity of the light chains of tetanus toxin and botulinum neurotoxin type A.

To define conserved domains within the light (L) chains of clostridial neurotoxins, we determined the sequence of botulinum neurotoxin type B (BoNT/B) and aligned it with those of tetanus toxin (TeTx) and BoNT/A, BoNT/C1, BoNT/D, and BoNT/E. The L chains of BoNT/B and TeTx share 51.6% identical amino acid residues whereas the degree of identity to other clostridial neurotoxins does not exceed 36.

The 24K protein of Borna disease virus.

Based on partial amino acid sequences obtained from tryptic peptides of the purified 24K antigen of Borna disease virus (BDV), we identified and sequenced four independent cDNA clones established from BDV-infected MDCK cells. Each of the clones encodes a polypeptide of 201 residues (Mr 22461) that differs considerably from an amino acid sequence published recently. In vitro transcription/translation of both the wild-type and a 5' truncated clone lacking the first ATG codon yielded a peptide that comigrates on electrophoresis with a polypeptide immunoprecipitated from BDV-infected cells.

Clostridial neurotoxins: from toxins to therapeutic tools?

Tetanus toxin and botulinum toxins are powerful neurotoxins which block neurotransmitter release through an unknown mechanism my means of their light chains. The heavy chains provide the machinery for neuroselective binding, internalization, retrograde intraaxonal transport, and translocation of the L-chains into the cytosole. We have cloned and sequenced the structural genes of tetanus toxin and of five serologically distinct botulinum toxins to identify structurally and functionally conserved subdomains.