ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 37, Number 2
JKCSEZ 37(2)
April 20, 1993 

The primary and secondary structure of the 5S rRNA isolated from Xanthomonas celebensis were determined by enzymatic and chemical degradation methods. It consists of 119 nucleotides and contains no modified nucleosides. As with the 5S rRNAs of X. maltophilia and X. citri, it contains an additional uridine residue on the 5'-terminus. Its secondary structure was almost identical to the models previously proposed by us for the 5S rRNA of two Xanthomonas species. Its secondary structure consists of five helices, five loops and two bulges. The tertiary interactions in the 5S rRNA molecule were analyzed by Fe(Ⅱ)-EDTA treatment and hybridization method using deoxyhexamer. From the fact that some adenine residues in loop M, region I1-C, loop H1, and loop H2 become susceptible to diethylpyrocarbonate when the 5S rRNA was hybridized with deoxyhexamer complementary to the sequence U35CCCAU40 and that some nucleotide residues in loop M, loop H1 and region D-I2 become resistant Fe(Ⅱ)-EDTA cleavage in the presence of Mg2+, it is presumed that loops H1 and H2 interact with loop M in some way. In the tertiary interaction, the regions I1-C and D-I2 seem to act as hinges in folding the stems B-I1-C and D-I2-E. It was found that loop H1 changes into a smaller loop of three bases by forming noncanonical A : C base-pairs ih acidic environment.