Due to the emergence of the SARS-CoV-2 virus, research on coronaviruses has been massively accelerated. In addition to SARS-CoV-2, there are other human infectious coronaviruses, including HCoV-229E. In all coronaviruses, secondary structure predictions indicate the presence of conserved structural elements in the 5'-untranslated region (5'-UTR). These conserved elements play crucial roles in RNA translation and replication. Stem-loop 5 (SL5), consisting of three substructures (5a, 5b, 5c), is highly conserved and harbours the start codon for viral translation. SL5 has repetitive structural motifs (RSMs), 5'-UUYYGU-3', which are conserved in many Alpha- and Betacoronaviruses. In the following, we present the 1H, 13C and 15N NMR resonance assignment of the SL5a RNA element from HCoV-229E and variations in the RSMs to show the effect of loop mutations on the structure of the hexaloop, revealing the different impact of each loop nucleotide on RNA dynamics.