J. Bacteriol., 10 1996, 5652-5659, Vol 178, No. 19
Copyright © 1996, American Society for Microbiology

Detection of an IS2-encoded 46-kilodalton protein capable of binding terminal repeats of IS2

ST Hu, LC Lee and GS Lei
Department of Microbiology, National Yang-Ming University, Taipei, Taiwan, Republic of China.

The genome of the transposable element IS2 contains five open reading frames that are capable of encoding proteins greater than 50 amino acids; however, only one IS2 protein of 14 kDa had been detected. By replacing the major IS2 promoter located in the right terminal repeat of IS2 with the T7 promoter to express IS2 genes, we have detected another IS2 protein of 46 kDa. This 46-kDa protein was designated InsAB'. Analyses of the InsAB' sequence revealed motifs that are characteristic of transposases of other transposable elements. InsAB' has the ability to bind both terminal repeat sequences of IS2. It was shown to bind a 27-bp sequence (5'-GTTAAGTGATAACAGATGTCTGGAAAT-3', positions 1316 to 1290 by our numbering system [16 to 42 by the previous numbering system]) located at the inner end of the right terminal repeat and a 31-bp sequence (5'- TTATTTAAGTGATATTGGTTGTCTGGAGATT-3', positions 46 to 16 [1286 to 1316]), including the last 27 bp of the inner end and the adjacent 4 bp of the left terminal repeat of IS2. This result suggests that InsAB' is a transposase of IS2. Since there is no open reading frame capable of encoding a 46-kDa protein in the entire IS2 genome, this 46-kDa protein is probably produced by a translational frameshifting mechanism.

This article has been cited by other articles:

• Haas, M., Rak, B. (2002). Escherichia coli Insertion Sequence IS150: Transposition via Circular and Linear Intermediates. J. Bacteriol. 184: 5833-5841 [Abstract] [Full Text]  
• Skaugen, M., Nes, I. F. (2000). Transposition in Lactobacillus sakei: inactivation of a second lactocin S operon by the insertion of IS1520, a new member of the IS3 family of insertion sequences. Microbiology 146: 1163-1169 [Abstract] [Full Text]  
• Hu, S.-T., Wang, H.-C., Lei, G.-S., Wang, S.-H. (1998). Negative Regulation of IS2 Transposition by the Cyclic AMP (cAMP)-cAMP Receptor Protein Complex. J. Bacteriol. 180: 2682-2688 [Abstract] [Full Text]