Enhancer-independent variants of phage Mu transposase: enhancer-specific stimulation of catalytic activity by a partner transposase.
Open Access
- 15 October 1995
- journal article
- Published by Cold Spring Harbor Laboratory in Genes & Development
- Vol. 9 (20), 2545-2555
- https://doi.org/10.1101/gad.9.20.2545
Abstract
Assembly of the functional tetrameric form of phage Mu transposase (A protein) requires specific interactions between the Mu A monomer and its cognate sequences at the ends of the Mu genome (attL and attR) as well as those internal to it (the enhancer element). We describe here deletion variants of Mu A that show enhancer-independence in the assembly of the strand cleavage complex. These deletions remove the amino-terminal region of Mu A required for its interactions with the enhancer elements. The basal enhancer-independent activity of the variant proteins can be stimulated by a partner variant harboring an intact enhancer-binding domain. By exploiting the identical att-binding, and nonidentical enhancer-binding specificities of Mu A and D108 A (transposase of the Mu related phage D108), we show that the stimulation of activity is enhancer-specific. Taken together, these results suggest that the domain of Mu A that includes the enhancer-interacting region may exert negative as well as positive modulatory effects on the strand cleavage reaction. We discuss the implications of these results in the framework of a recent model for the assembly of shared active sites within the Mu A tetramer.Keywords
This publication has 34 references indexed in Scilit:
- DNA-Protein Cooperativity in the Assembly and Stabilization of Mu Strand Transfer Complex: Relevance of DNA Phasing and att Site CleavageJournal of Molecular Biology, 1994
- Alignment of recombination sites in Hin-mediated site-specific DNA recombination.Genes & Development, 1991
- Configuration of DNA strands and mechanism of strand exchange in the Hin invertasome as revealed by analysis of recombinant knots.Genes & Development, 1991
- Two mutations of phage Mu transposase that affect strand transfer or interactions with B protein lie in distinct polypeptide domainsJournal of Molecular Biology, 1991
- The Hin Invertasome: Protein-Mediated Joining of Distant Recombination Sites at the EnhancerScience, 1990
- Processive recombination by the phage Mu Gin system: Implications for the mechanisms of DNA strand exchange, DNA site alignment, and enhancer actionCell, 1990
- Carboxyl-terminal mutants of phage Mu transposaseJournal of Genetics, 1986
- Role of DNA topology in Mu transposition: Mechanism of sensing the relative orientation of two DNA segmentsCell, 1986
- Hin-mediated site-specific recombination requires two 26 by recombination sites and a 60 by recombinational enhancerCell, 1985
- G inversion in bacteriophage Mu DNA is stimulated by a site within the invertase gene and a host factorCell, 1985