Showing papers by "Harry F. Noller published in 1977"
TL;DR: The relatively small number of kethoxal-reactive sites in 23 S RNA that is strongly protected in 70 S ribosomes suggests that subunit association may involve contacts between single-stranded sites in 16 S RNA and 50 S subunit proteins or non-Watson-Crick interactions with 23 SRNA.
124 citations
TL;DR: It is concluded that protein L18 increases the secondary, and possible the tertiary structure of 5S RNA, and exerts a minor stabilizing effect on its conformation while protein L25 causes a small decrease in 5SRNA secondary structure.
Abstract: The effects of ribosomal proteins L18, L25 and L5 on the conformation of 5S RNA have been studied by circular dichroism and temperature dependent ultraviolet absorbance. The circular dichroism spectrum of native 5S RNA is characterized in the near ultraviolet by a large positive band at 267 nm and a small negative band at 298 nm. The greatest perturbation in the spectrum was produced by protein L18 which induced a 20% increase in the 267 nm band and no change in the 298 nm band. By contrast, protein L25 caused a small decrease in both bands. No effect was observed with protein L5. Simultaneous binding of proteins L18 and L25 resulted in CD changes equivalent to the sum of their independent effects. The UV absorbance thermal denaturation profile of the 5S RNA L18 complex lacked the pre-melting behavior characteristic of 5S RNA. Protein L25 had no effect on the 5S RNA melting profile. We concluded that protein L18 increases the secondary, and possible the tertiary structure of 5S RNA, and exerts a minor stabilizing effect on its conformation while protein L25 causes a small decrease in 5S RNA secondary structure. The implications of these findings for ribosome assembly and function are discussed.
40 citations