Phylogeny of the conserved 3' terminal structure of the RNA of small ribosomal subunits.

AUTOR(ES)

Van Knippenberg, P H

RESUMO

The strongest conserved part of the RNA of small ribosomal subunits is probably located near the 3' end. This paper reviews the primary and secondary structures of some 40 sequenced 3' termini and tries to classify these structures according to common features and differences. The regions under consideration contain at the 5' side an almost universal, supposedly single-stranded stretch of nucleotides with the sequence--AAGUCGUAACAAGGU--. This is followed by a stem-loop structure. The stem always contains 9 basepairs (including U-G pairs) and no mismatches or bulged nucleotides. The loop of the hairpin is either (m2)GGm62Am62A (bacteria, chloroplasts and mitochondria) or UGm62Am62A (cytoplasm). The hairpin is, in most cases, followed at the 3' side by--GGAUCA--. Next to it bacteria and chloroplasts contain the so-called "Shine and Dalgarno" sequence --CCUCC--. The stem region of the hairpin contains a conserved A-U U-G junction. The two basepairs between this junction and the loop are either of type 1 (G-C G-C) or type 2 (C-G C-G). Classification according to type links certain bacteria with mitochondria of yeast and plants and others with chloroplasts and with animal mitochondria.

Documentos Relacionados

• Fluorescence studies of the accessibility of the 3' ends of the ribosomal RNAs in Escherichia coli ribosomes and subunits.
• Nonribosomal proteins associated with eukaryotic native small ribosomal subunits.
• Binding of specific sRNA to 30S ribosomal subunits: effect of 50S ribosomal subunits.
• Cluster of genes in Escherichia coli for ribosomal proteins, ribosomal RNA, and RNA polymerase subunits.
• Sequence determination of the 3' terminal T1 oligonucleotide of 18S ribosomal RNA.