Skip to content
Login Register

#16S rRNA

3 public questions tagged with this topic.

Microbial Physiology

Which scientist introduced the three-domain system based on 16S rRNA sequencing?

Prior to molecular phylogeny, life was divided into five kingdoms based on morphology, staining, and physiology. Carl Woese revolutionized classification in late 1970s by utilizing chronometer molecules that evolve slowly and are universally distributed, specifically 16S ribosomal RNA for prokaryotes and 18S rRNA for eukaryotes. By comparing oligonucleotide catalogs and later full sequences, he uncovered that methanogens and other extremophiles formed lineage as divergent from typical bacteria as bacteria were from eukaryotes. This led to proposal of three primary domains: Bacteria, Archaea, a

Ref: Woese et al., PNAS 1990, Towards a Natural System; Sapp, Microbe 2007, The Three-Domain System.

View Details
Translation Basics

Which rRNA interacts with Shine–Dalgarno sequence?

Shine-Dalgarno sequence AGGAGG located five to nine nucleotides upstream of start codon in bacterial mRNA base-pairs with anti-Shine-Dalgarno CCUCCU at 3' terminus of 16S rRNA in 30S subunit. This RNA-RNA duplex anchors mRNA on ribosome, aligns AUG in P-site for initiator tRNA binding, facilitating 30S pre-initiation complex formation. Strength of pairing modulates translation initiation efficiency across cistrons in polycistronic mRNAs. Eukaryotes lack Shine-Dalgarno, using 5' cap and Kozak context for scanning-dependent initiation instead of internal base-pairing mechanism. This refined regu

Ref: Berg et al., Biochemistry, 9th ed., Chapter 32, Shine-Dalgarno interaction with 16S anti-SD sequence

View Details
Acid, Base, pH

Shine–Dalgarno sequence interacts with

16S rRNA accurately identifies the binding site, binding partner, or molecular interaction described in this question. In Acid, Base, pH, molecular recognition and binding specificity are governed by complementary shape, charge, and hydrophobic interactions between molecules. 16S rRNA binds at the specified location due to its structural complementarity and specific non-covalent or covalent interactions. The other options (23S rRNA, 18S rRNA, and 28S rRNA) describe binding to different sites, involve different types of molecular interactions, or represent incorrect binding partners.

Ref: Lehninger Principles of Biochemistry, Nelson & Cox, 8th Ed., Ch. 2

View Details