Open AccessCD spectra of 5-methyl-2-thiouridine in tRNAfMet from an extreme thermophile
Author(s) -
Kimitsuna Watanabe,
Tairo Oshima,
Susumu Nishimura
Publication year - 1976
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/3.7.1703
Subject(s) - thermophile , biology , transfer rna , monomer , oligonucleotide , base pair , biochemistry , crystallography , microbiology and biotechnology , rna , dna , polymer , materials science , enzyme , gene , chemistry , composite material
5-Methyl-2-thiouridine (S) in tRNA-Met-f from an extreme thermophile is located in the TpsiC region, replacing T, and has a positive CD band centered at 310 nm. Upon heating, the profiles of the change in this band were similar to the UV melting profiles of the change monitored at 260 nm. This strongly suggests a close relation between heat denaturation of the tRNA and the conformation of the S base. Oligonucleotides containing S showed negative CD bands at 320-330 nm, like the monomer S itself, but when the 3'-2/5 fragment containing S formed a complex with the complementary 5'-3/5 fragment, a positive CD band appeared at 310 nm. These results suggest that combination of the TpsiC loop containing S with the hU loop is necessary for the positive band of S at 310 nm. S may serve to strengthen the association of the TpsiC loop with the hU loop in tRNA of the thermophile.