Nucleic Acids Research, 1978, Vol. 5, No. 2 307-315
© 1978
Articles |
360 MHz PMR studies on the involvement of the Y-nucleoside in the conformation of 2' -OMeGpApApYpAp
from torula yeast tRNAphe*
Department of Chemistry, California State University Los Angeles, CA 90032 +Hyland Laboratories Costa Mesa, CA 92626 ++Varian Associates Florham Park, NJ 07932 **Department of Biopharmaceutical Sciences, University of Utah Salt Lake City, UT 84112, USA
Address correspondence to this author
Received September 28, 1977.
360 MHz measurements of chemical shifts, 3J1'–2', and T1. as a function of temperature for various protons of the hexanucleotide 2'-0MeGpApApYpAp
from torula yeast tRNAPhe have revealed a unique involvement of the Yt base in the structure and conformation of this oligonucleotide. Whereas the adenosine residues in the anticodon triplet are relatively stable to temperature increase, the Yt readily undergoes destacking and a change in ribose conformation. The destacking most likely involves a torsional displacement of the Yt base occasioned by a rotation of the phosphateribose backbone. The possible relevance of this unusual behavior to the influence of the Yt residue in tRNA function in protein biosynthesis is discussed.
* Work performed at ICN Pharmaceuticals, Inc., Irvine, CA; the Stanford Magnetic Resonance Laboratory, Stanford, CA and the California State University, Los Angeles, CA. Supported in part by grant RR 00711 from the National Institute of Health. Presented at the 18th Experimental NMR Conference, Asilomar, CA., April, 1977.