Send to:

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 2006 Sep 12;103(37):13750-2. Epub 2006 Sep 1.

Chiral-selective aminoacylation of an RNA minihelix: Mechanistic features and chiral suppression.

Author information

  • 1The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.


Aminoacylation of RNA minihelices is speculated to be a key step in the transition from the putative RNA world to the theater of proteins. This reaction affords the opportunity to make chiral selection of an l- or d-amino acid and thus determine the ultimate chirality that is incorporated into proteins. Previous work showed chiral preference of aminoacylation with a nonprotein, nonribozyme, RNA-directed aminoacylation system. This preference was, in turn, determined by the preexisting chirality of the RNA. The alpha-amino group attached to the asymmetric alpha-carbon of the amino acid was an obvious candidate to play a role in chiral selectivity through interactions with the RNA. Also not clear was whether a simple manipulation could change the chiral selectivity, thereby giving insight into the basis of chiral selection in the first place. Here we show, surprisingly, no role for the free alpha-amino group in chiral selection. However, by a sequence manipulation, chiral preference was suppressed and partly reversed. This result and those with further RNA constructs support the idea that the chiral preference for an l-amino acid in these constructs depends on avoiding a sugar-pucker-sensitive steric clash between a pendant group of a base with the amino acid side chain.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk