Format

Send to

Choose Destination
See comment in PubMed Commons below
J Mol Evol. 2005 Aug;61(2):226-35. Epub 2005 Jun 27.

RNA affinity for molecular L-histidine; genetic code origins.

Author information

1
Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309-0347, USA.

Abstract

Selection for affinity for free histidine yields a single RNA aptamer, which was isolated 54 times independently. This RNA is highly specific for the side chain and binds protonated L-histidine with 10(2)-10(3)-fold stereoselectivity and a dissociation constant (K(D)) of 8-54 microM in different isolates. These histidine-binding RNAs have a common internal loop-hairpin loop structure, based on a conserved RAAGUGGGKKN(0-36) AUGUN(0-2)AGKAACAG sequence. Notably, the repetitively isolated sequence contains two histidine anticodons, both implicated by conservation and chemical data in amino acid affinity. This site is probably the simplest structure that can meet our histidine affinity selection, which strengthens experimental support for a "stereochemical" origin of the genetic code.

PMID:
15999244
DOI:
10.1007/s00239-004-0360-9
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Springer
    Loading ...
    Support Center