Identification of an insertion-sequence-like genetic element in the newly recognized human pathogen Mycoplasma incognitus.
Cloned 2.2-kb DNA (plasmid psb-2.2) of Mycoplasma incognitus, a pathogen in AIDS and non-AIDS patients [Lo et al., Am. J. Trop. Med. Hyg. 41 (1989) 364-376; 601-616], contains a 1405-bp genetic element closely resembling bacterial insertion sequence (IS) elements. This IS-like element has 29-bp terminal inverted repeats with seven mismatches, is immediately flanked by 3-bp direct repeats, and has typical stem-and-loop structures at or near both the termini. Two potential open reading frames (ORF-1 and ORF-2) encode 143 amino acids (aa) and 103 aa, respectively, in this IS-like element. Part (57 aa) of the deduced aa sequence of ORF-2 has a significant homology (43%) with the putative transposase of Escherichia coli IS3. In this study, a series of synthetic oligodeoxyribonucleotides each containing a specific sequence of a selected segment in psb-2.2, have been used as probes which reveal that the IS-like element occurs more than ten times in the genome of M. incognitus. This potentially transposable element has many characteristic features in common with bacterial IS elements.
Hu
W S
WS
Department of Infectious and Parasitic Diseases Pathology, Armed Forces Institute of Pathology, Washington, DC 20306.
Wang
R Y
RY
Liou
R S
RS
Shih
J W
JW
Lo
S C
SC
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D009174:Mycoplasma / Q000235:genetics* / Q000472:pathogenicity; D012091:Repetitive Sequences, Nucleic Acid
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial