Biomedical subjects

T Haselman

Publications and source records attributed to T Haselman.

3 recordsLinked to original sources

PubMed1989

Phylogenetic evidence for tertiary interactions in 16S-like ribosomal RNA.

Major efforts are underway to elucidate the spatial distribution of ribosomal RNAs (rRNAs) in the ribosome. An especially informative approach is the identification of likely base-base tertiary interactions within the RNA by phylogenetic comparison. Herein evidence is presented for three heretofore unrecognized candidate tertiary interactions, G506/C525, C779/G803 and A994/U1380 (1) in 16S-like rRNAs. This brings to eight the number of such interactions that are strongly supported by phylogenetic evidence. The three newly identified interactions further define the folding within domains II and III of 16S-like rRNA. No interactions have yet been found that would serve to orient the domains relative to one another.

Animals↗

PubMed1989

Additional Watson-Crick interactions suggest a structural core in large subunit ribosomal RNA.

Two new Watson-Crick type interactions in 23S-like ribosomal RNA have been identified by comparative sequence analysis. These interactions, A1269/U2011 and C1270/G2010 (E. coli numbering) along with the previously proposed A1262/U2017 suggest an anti-parallel helical arrangement characteristic of secondary structure in the 1265/2015 region of 23S rRNA. Nested within these three interactions are three universal juxtapositions which in principle allow the formation of an irregular helix containing two additional A-G interactions and a universal A-U pair. Whether or not this extended helix is biologically significant is uncertain. The proponderance of interactions in the 1265/2015 region and its location relative to the known structural domains of 23S rRNA suggest that this region may be part of a central structural core similar to that already known in 16S rRNA.

Animals↗

PubMed1988

Fidelity of secondary and tertiary interactions in tRNA.

Contingency table analysis has previously been used to detect sequence correlations in RNAs caused by either secondary or tertiary interactions. An approach known as matrix reduction is developed here as an alternative to the usual Chi square test. This approach is especially sensitive to covariation between equivalent positions and is effective at detecting tertiary interactions that exhibit such covariation. Matrix reduction was also effective at detecting Watson-Crick base-pairs that exhibit a high degree of pairing fidelity. The method was applied to five closely related structural classes of tRNA and a number of tertiary interactions were detected in each class.

Base Composition↗